RU2774435C2 - Method and device for security provision - Google Patents

Abstract

FIELD: data protection.

SUBSTANCE: invention relates to means for providing security of a non-access stratum (hereinafter – NAS) message. A value of the first parameter indicating an access technology used for the transmission of NAS message is determined using a device. The first parameter is an input parameter used, when security provision for the transmission of NAS message is performed. Security provision for NAS message is performed using the device based on the first parameter, NAS key and NAS COUNT corresponding to the access technology used for the transmission of NAS message, wherein the specified device is a terminal device, a microcircuit in the terminal device or a base network device.

EFFECT: increase in data security during the transmission via NAS line of the connection between a terminal device and AMF node.

27 cl, 16 dwg

Description

The field of technology to which the invention relates

Embodiments of the present invention relate to the field of wireless communication technologies and, in particular, to a security method and apparatus.

State of the art

In a 5th generation ( ^5G ) system, an end device can access an access and mobility management function (AMF) node only through a 3rd ^generation partnership project access technology. , 3GPP), either with non-3GPP access technology only (non-3GPP), or with 3GPP access technology and non-3GPP access technology. When a terminal device accesses an AMF node through 3GPP access technology and non-3GPP access technology, two non-access stratum (NAS) connection lines are simultaneously used between the terminal device and the AMF node. If an end device uses one set of NAS keys and one set of NAS COUNTs (NAS count) to secure two links separately, the following case may occur: an AMF node first receives a relatively small NAS COUNT sent over one link, and then receives a relatively large NAS COUNT transmitted via another link. Therefore, a replay attack occurs, leading to a decrease in the security of data in transit over the NAS connection line between the end device and the AMF node. In this regard, it is necessary to solve the technical problem of ensuring the security of data transmission between the terminal device and the AMF node over multiple NAS connection lines, if any.

Disclosure of the essence of the invention

Embodiments of the present invention provide a method and apparatus for implementing security for multiple NAS connection lines.

To solve the above problems, the following technical solutions are provided in the embodiments of the present invention:

An embodiment of the present invention provides a security method. The method includes: determining by the terminal a first parameter and then performing security for the NAS message based on the first parameter, the NAS key and the NAS COUNT corresponding to the access technology used to transmit the NAS message. The first parameter is an input parameter used when the terminal performs security for the NAS message and is used to indicate the access technology used to transmit the NAS message. The tag may support at least two access technologies and may separately support a corresponding NAS COUNT for each of the at least two access technologies.

For example, the at least two access technologies supported by the terminal may include a 3GPP access technology and another access technology that may share a 3GPP network core network device with a 3GPP access technology. The other access technology may be, for example, a non-3GPP access technology or a fixed network access technology.

Alternatively, the first parameter may further be used to indicate the transmission path used by the terminal to transmit the NAS message, and the terminal may separately maintain a corresponding NAS COUNT for each transmission path used to transmit the NAS messages.

The first parameter may be an input parameter newly added in the encryption/decryption process or integrity protection process, such as the ACCESS parameter. The ACCESS bit of the parameter may be set to different values to represent different access technologies. For example, if the first parameter is 00, then this indicates that the 3GPP access technology is being used; or, if the first parameter is 01, then this indicates that a non-3GPP access technology is being used. Alternatively, the first parameter may be all or some bits of the current COUNT input parameter in the encryption/decryption process or integrity protection process, or the first parameter may be all or some bits of the current BEARER input parameter in the encryption/decryption process or integrity protection process.

The NAS key is shared by at least two access technologies supported by the end device.

According to this method, the tag may separately maintain the corresponding NAS COUNTs for each of the at least two access technologies. An end device does not use the same set of NAS COUNTs when transmitting NAS messages over different access technologies. Instead, the end device performs security for the NAS message using the NAS COUNT supported for the respective access technology. Can avoid a replay attack that occurs when the underlying network device first receives a relatively small NAS COUNT transmitted on one link and then receives a relatively large NAS COUNT transmitted on another link. Additionally, in the present invention, the first parameter used to distinguish between different access technologies is additionally used when securing the NAS message. Therefore, even if the same NAS key and the same NAS COUNT are used when performing security for a NAS message transmitted using different access technologies, the security results for the NAS message are different, which reduces the probability of occurrence of a replay attack, the more thereby realizing security for multiple NAS connection lines.

In an exemplary implementation, the at least two access technologies include a first access technology. If the access technology used to send the NAS message is the first access technology, then before the terminal determines the first parameter, the terminal may determine the first uplink NAS COUNT corresponding to the first access technology, and then the terminal sends the first message to the underlying network device where security is performed on the first message using the first uplink NAS COUNT and the NAS key, and the first message contains some or all of the bits of the first uplink NAS COUNT.

For example, the first access technology may be a non-3GPP access technology.

In an exemplary implementation, the initial value of the first uplink NAS COUNT is 0, with some or all of the bits of the first uplink NAS COUNT being 0. Alternatively, the first uplink NAS COUNT is a random number. In particular, some or all of the bits in the first uplink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part in the first uplink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the at least two access technologies further include a second access technology, and the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the second access technology and that is stored end device. If the terminal stores at least two uplink NAS COUNTs corresponding to the second access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that corresponds to the second access technology and is stored by the terminal. Alternatively, the at least two access technologies further include a second access technology, and the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the second access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the second access technology, the first uplink NAS COUNT is the sum of 1 and the largest uplink NAS COUNT that corresponds to the second access technology and is stored by the terminal. Alternatively, the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the first access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the first access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that corresponds to the first access technology and is stored by the terminal. Alternatively, the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the first access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the first access technology, the first uplink NAS COUNT is the sum of 1 and the largest uplink NAS COUNT that corresponds to the first access technology and is stored by the terminal.

In another possible implementation, the at least two access technologies include a first access technology and a second access technology. If the access technology used to send the NAS message is the first access technology, before the end device determines the first parameter, the end device can send the first message to the underlying network device while securing the first message using the NAS key and uplink NAS COUNT corresponding to the second access technology, and the first message contains some or all bits of the uplink NAS COUNT corresponding to the second access technology.

The second access technology is a 3GPP access technology. Alternatively, a prerequisite for implementing this implementation is that the terminal device has gained access to the underlying network device via 3GPP access technology.

In an exemplary implementation, the first message may contain first indication information, and the first indication information is used to indicate the access technology corresponding to some or all of the uplink NAS COUNT bits carried in the first message. Alternatively, the first indication information may be further used to indicate a transmission path corresponding to some or all of the uplink NAS COUNT bits transmitted in the first message.

In an exemplary implementation, the tag receives a second message from the host network device, where the second message includes one or both of the second uplink NAS COUNT and the first downlink NAS COUNT that correspond to the first access technology.

Alternatively, the second message may include a first downlink NAS COUNT corresponding to the first access technology. Alternatively, the second message includes both the second uplink NAS COUNT and the first downlink NAS COUNT, which correspond to the first access technology.

Alternatively, the second uplink NAS COUNT and the first downlink NAS COUNT that correspond to the first access technology are the same.

In an exemplary implementation, the second uplink NAS COUNT is initialized to 0, with all or some bits of the second uplink NAS COUNT being 0. Alternatively, the second uplink NAS COUNT is a random number. In particular, some or all of the bits in the second uplink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part of the second uplink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the second uplink NAS COUNT is a downlink NAS COUNT that corresponds to the second access technology and that is stored by the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the second uplink NAS COUNT is the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the second access technology and which is stored by the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. device. Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the first access technology and which is stored by the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the first access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the first access technology and which is stored by the core network device. Alternatively, the second uplink NAS COUNT is the first uplink NAS COUNT; or the second uplink NAS COUNT is the sum of 1 and the first uplink NAS COUNT.

In an exemplary embodiment, the initial value of the first downlink NAS COUNT is 0, where all or some bits of the first downlink NAS COUNT are 0. Alternatively, the first downlink NAS COUNT is a random number. In particular, some or all of the bits in the first downlink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part of the first downlink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the first downlink NAS COUNT is a downlink NAS COUNT which corresponds to the second access technology and which is stored by the network core device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the first downlink NAS COUNT is the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. Alternatively, the first downlink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the second access technology and which is stored by the underlying network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the first downlink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the second access technology and which is stored in the main network device. Alternatively, the first downlink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the first access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the first access technology, the first downlink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the first access technology and is stored in the main network device.

In an exemplary implementation, the second message contains second indication information, and the second indication information is used to indicate the access technology corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information used to indicate the second uplink NAS COUNT transmitted in the second message.

Alternatively, the second indication information is used to indicate the transmission path corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information that is used to indicate a transmission path corresponding to the second uplink NAS COUNT transmitted in the second message.

According to a second aspect, an embodiment of the present invention provides a security method. The method includes:

determining by the main network device the first parameter; then, the NAS master network security device executes the message based on the first parameter, the NAS key and the NAS COUNT corresponding to the access technology used to send the NAS message. The first parameter is used to specify the access technology used to send the message to the NAS. The underlying network device may separately support a corresponding NAS COUNT for each of the at least two access technologies supported by the terminal device.

For example, the at least two access technologies supported by a terminal may include a 3GPP access technology and another access technology. Said other access technology may be, for example, a non-3GPP access technology or a fixed network access technology.

Alternatively, the first parameter may be further used to indicate the transmission path used by the underlying network device to transmit the NAS message, and the underlying network device may separately maintain a corresponding NAS COUNT for each transmission path used to transmit the NAS messages.

The first parameter may be an input parameter newly added in the encryption/decryption process, or an integrity protection process such as the ACCESS parameter. The ACCESS bit of the parameter may be set to different values to represent different access technologies. For example, if the first parameter is 00, the 3GPP access technology is used; or, if the first parameter is 01, non-3GPP access technology is used. Alternatively, the first parameter may further be all or some bits of the current COUNT input parameter in the encryption/decryption process, or the integrity protection process. Alternatively, the first parameter may be all or some bits of the current BEARER input parameter in the encryption/decryption process, or integrity protection process.

The NAS key is shared by at least two access technologies supported by the end device.

According to this method, the underlying network device may separately maintain respective NAS COUNTs for each of the at least two access technologies. An end device does not use the same set of NAS COUNTs when transmitting a NAS message using different access technologies. Instead, the underlying network device secures the NAS message with the NAS COUNT supported for the corresponding access technology. This can prevent a replay attack that occurs when a terminal first receives a relatively small NAS COUNT transmitted on one link and then receives a relatively large NAS COUNT transmitted on another link. Further, in the present invention, the first parameter used to distinguish between different access technologies is further used in securing the NAS message. Therefore, even when using the same NAS key and the same NAS COUNT, while securing the NAS message transmitted using different access technologies, the results of protecting the NAS message are different, which reduces the possibility of replay attack, thereby realizing the security for multiple NAS links.

In an exemplary implementation, the at least two access technologies include a first access technology. If the access technology used to transmit the NAS message is the first access technology, then before the main network device determines the first parameter, the main network device can receive the first message, security is provided for the first message using the NAS key and the first uplink NAS COUNT connection corresponding to the first access technology, and the first message contains the first uplink NAS COUNT.

For example, the first access technology may be a non-3GPP access technology.

In an exemplary implementation, the initial value of the first uplink NAS COUNT is 0, wherein some or all of the bits of the first uplink NAS COUNT are 0. Alternatively, the first uplink NAS COUNT is a random number. In particular, some or all of the bits in the first uplink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part in the first uplink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the at least two access technologies further include a second access technology, and the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the second access technology and that is stored end device. If the terminal stores at least two uplink NAS COUNTs corresponding to the second access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that corresponds to the second access technology and is stored by the terminal. Alternatively, the at least two access technologies further include a second access technology, and the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the second access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the second access technology, the first uplink NAS COUNT is the sum of 1 and the largest uplink NAS COUNT that corresponds to the second access technology and is stored by the terminal. Alternatively, the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the first access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the first access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that corresponds to the first access technology and is stored by the terminal. Alternatively, the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the first access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the first access technology, the first uplink NAS COUNT is the sum of 1 and the largest uplink NAS COUNT that corresponds to the first access technology and is stored by the terminal.

In another possible implementation, the at least two access technologies include a first access technology and a second access technology. If the access technology used to transmit the NAS message is the first access technology, then before the main network device determines the first parameter, the main network device can receive the first message, where security for the first message is provided using the NAS key and the uplink NAS COUNT connection corresponding to the second access technology, and the first message contains some or all bits of the uplink NAS COUNT corresponding to the second access technology.

The second access technology is a 3GPP access technology. Alternatively, a prerequisite for this implementation is that the terminal device has accessed the underlying network device using 3GPP access technology.

In an exemplary implementation, the first message conveys the first indication information, and the first indication information is used to indicate the access technology corresponding to some or all of the uplink NAS COUNT bits transmitted in the first message. Alternatively, the first indication information may be further used to indicate a transmission path corresponding to some or all of the uplink NAS COUNT bits transmitted in the first message.

In a possible implementation, after the main network device receives the first message from the terminal device, the main network device checks, according to the uplink NAS COUNT corresponding to the access technology indicated by the first indication information, some or all of the bits of the NAS COUNT transmitted in the first message.

In this embodiment of the present invention, the core network device can independently maintain the NAS COUNT for 3GPP access technology and the NAS COUNT for non-3GPP access technology, and further verify the received uplink NAS COUNT according to the uplink NAS COUNT supported by the core network device, thereby , reducing the likelihood of a repetition attack occurring.

In an exemplary implementation, the core network device determines one or both of the second uplink NAS COUNT and the first downlink NAS COUNT that correspond to the first access technology, and then the core network device sends a second message to the terminal device, where the second message includes one or both the second uplink NAS COUNT and the first downlink NAS COUNT, which correspond to the first access technology.

Alternatively, the second message may include a first downlink NAS COUNT corresponding to the first access technology. Alternatively, the second message includes both the second uplink NAS COUNT and the first downlink NAS COUNT, which correspond to the first access technology.

Alternatively, the second uplink NAS COUNT and the first downlink NAS COUNT that correspond to the first access technology are the same.

In an exemplary implementation, the second uplink NAS COUNT is initialized to 0, with all or some bits of the second uplink NAS COUNT being 0. Alternatively, the second uplink NAS COUNT is a random number. In particular, some or all of the bits in the second uplink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part of the second uplink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the second uplink NAS COUNT is a downlink NAS COUNT that corresponds to the second access technology and that is stored by the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the second uplink NAS COUNT is the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the second access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the second access technology and which is stored in the main network device. Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the first access technology and which is stored in the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the first access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the first access technology and which is stored by the core network device. Alternatively, the second uplink NAS COUNT is the first uplink NAS COUNT; or the second uplink NAS COUNT is the sum of 1 and the first uplink NAS COUNT.

In an exemplary implementation, the initial value of the first downlink NAS COUNT is 0, wherein all or some bits of the first downlink NAS COUNT are 0. Alternatively, the first downlink NAS COUNT is a random number. In particular, some or all of the bits in the first downlink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part of the first downlink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the first downlink NAS COUNT is a downlink NAS COUNT which corresponds to the second access technology and which is stored in the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the first downlink NAS COUNT is the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. Alternatively, the first downlink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the second access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the first downlink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the second access technology and which is stored primarily network device. Alternatively, the first downlink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the first access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the first access technology, the first downlink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the first access technology and which is stored mainly network device.

In an exemplary implementation, the second message contains second indication information, and the second indication information is used to indicate the access technology corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information used to indicate the second uplink NAS COUNT transmitted in the second message.

Alternatively, the second indication information is used to indicate the transmission path corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information that is used to indicate a transmission path corresponding to the second uplink NAS COUNT transmitted in the second message.

Alternatively, the second indication information is used to indicate the transmission path corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information that is used to indicate a transmission path corresponding to the second uplink NAS COUNT transmitted in the second message.

According to a third aspect, an embodiment of the present invention provides a device, and the device has a function of realizing the actions of a terminal device in the above implementation of the method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function. For example, the device may be a terminal device, or may be a chip in a terminal device.

In an exemplary implementation, the device is a terminal device and the terminal device includes a processor. The processor is configured to support the tag while performing a corresponding function in the above method. In addition, the terminal device may further include a transmitter and a receiver, where the transmitter and receiver are configured to communicate between the terminal device and the main network device. In addition, the terminal device may further include a memory, and the memory is configured to be connected to the processor and store the necessary program instructions and data that the terminal device needs.

According to a fourth aspect, an embodiment of the present invention provides a device, and the device has a function of realizing the actions of the main network device in the above implementation of the method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function. For example, the device may be a primary network device, or may be a chip in a primary network device.

In an exemplary implementation, the device is a primary network device, and the primary network device includes a processor. The processor is configured to support the host network device while performing the corresponding function in the above method. Additionally, the host network device may further include a transmitter and a receiver, where the transmitter and receiver are configured to communicate between the host network device and the terminal device. Additionally, the host network device may further include a memory, and the memory is configured to be coupled to the processor and store program instructions and data that are needed by the terminal device.

According to a fifth aspect, an embodiment of the present invention provides a communication system, where the system includes a terminal device and a host network device described in the preceding aspects. Alternatively, the system may further include a base station, an N3IWF node, and a tag and host network device described in the preceding aspects.

According to a sixth aspect, an embodiment of the present invention provides a computer storage medium configured to store a computer software instruction used by the above terminal device, where the computer software instruction includes a program for executing the first aspect.

According to a seventh aspect, an embodiment of the present invention provides a computer storage medium capable of storing a computer software instruction used by the above-mentioned core network device. The computer software instruction includes a program for performing the second aspect.

According to an eighth aspect, an embodiment of the present invention provides a computer program product including an instruction. When the computer executes the instruction, the computer is configured to execute the method in the first aspect.

According to a ninth aspect, an embodiment of the present invention provides a computer program product including an instruction. When the computer executes the instruction, the computer may execute the method in the second aspect.

According to a tenth aspect, an embodiment of the present invention provides a chip system applied to a terminal device, where the chip system includes at least one processor, a memory, and a transceiver circuit. The memory, the transceiver circuitry, and at least one processor are connected to each other via communication lines. An instruction is stored in at least one memory. The instruction is executed by the processor to perform terminal operations in the manner described in the first aspect.

According to an eleventh aspect, an embodiment of the present invention provides a chip system applied to a core network device, where the chip system includes at least one processor, a memory, and a transceiver circuit. The memory, the transceiver circuitry, and at least one processor are connected to each other via communication lines. An instruction is stored in at least one memory. The instruction is executed by the processor to perform operations of the main network device in the manner described in the second aspect.

According to the security method provided in the embodiments of the present invention, a terminal may separately maintain a corresponding NAS COUNT for each of at least two access technologies. An end device does not use the same set of NAS COUNTs when transmitting a NAS message over different access technologies. Instead, the end device secures the NAS message using the NAS COUNT supported for the respective access technology. This can prevent a replay attack that occurs when the underlying network device first receives a relatively small NAS COUNT transmitted on one link and then receives a relatively large NAS COUNT transmitted on another link. Additionally, the present invention further uses the first parameter used to distinguish between different access technologies to secure the NAS message. Therefore, even if the same NAS key and the same NAS COUNT are used, when securing a NAS message transmitted using different access technologies, the results of protecting the NAS message are different, which reduces the possibility of replay attack, thereby ensuring security. for multiple NAS links.

Brief description of the drawings

Fig. 1 is a diagram of a possible network architecture according to an embodiment of the present invention;

fig. 2 is a diagram of another possible network architecture according to an embodiment of the present invention;

fig. 3 is an example diagram of an encryption and decryption method according to an embodiment of the present invention;

fig. 4 is an exemplary diagram of an integrity security method according to an embodiment of the present invention;

fig. 5 is a flowchart of a security method according to an embodiment of the present invention;

fig. 6 is an example of a diagram of another encryption and decryption method according to an embodiment of the present invention;

fig. 7 is an example of a diagram of another encryption and decryption method according to an embodiment of the present invention;

fig. 8 is an example of a diagram of another encryption and decryption method according to an embodiment of the present invention;

fig. 9 is a flowchart of another security method according to an embodiment of the present invention;

fig. 10 is a flowchart of yet another security method according to an embodiment of the present invention;

fig. 11A and FIG. 11B are flow charts of yet another security method in accordance with an embodiment of the present invention;

fig. 12 is a block diagram of an apparatus according to an embodiment of the present invention;

fig. 13 is a block diagram of a terminal device according to an embodiment of the present invention;

fig. 14 is a block diagram of another device according to an embodiment of the present invention; and

fig. 15 is a block diagram of a main network device according to an embodiment of the present invention.

Implementation of the invention

The present invention will now be described in detail with reference to the accompanying drawings. The particular mode of operation in the method embodiments may apply to a device embodiment or a system embodiment. In the descriptions of the present invention, unless otherwise indicated, "many" means two or more than two.

The system architecture and service scenario described in this document is intended to more clearly describe the technical solutions of the present invention, but is not intended to limit the technical solutions presented in the present invention. A person skilled in the art may be aware that, as the system architecture evolves and a new service scenario emerges, the technical solutions presented in the present invention are also applicable to a similar technical problem.

It should be noted that in the present invention, a term such as "example" or "for example" is used as an example to provide an illustration or description. Any embodiment or design described as "example" or "for example" in the present invention should not be explained as preferable or having more advantages than another embodiment or design. Specifically, the use of the word "example" or "for example" or the like is intended to represent the relevant concept in a certain way.

Embodiments of the present invention can be applied to a next generation wireless communication system, such as a 5G communication system. In FIG. 1 shows a diagram of a possible network architecture in accordance with the present invention. The network architecture includes the following.

An AMF node is a network element capable of managing mobility, and may be configured to implement a function other than session management in functions of a mobility management entity (MME), such as a function such as lawful interception or access authorization .

The session management function (SMF) node is configured to allocate a user plane session resource.

The authentication server function (AUSF) node is configured to: when the AUSF node performs authentication on the terminal device, verify and transmit a parameter to be authenticated, and authenticate the terminal device authentication. The main functions include: receiving an authentication request sent by a security anchor function (SEAF) node and selecting an authentication method. When using the extensible authentication protocol authentication and key agreement (EAP-AKA') 3rd generation authentication protocol method, the AUSF node can complete network side endpoint authentication.

The SEAF node may be part of an AMF node, or may be an independent network element, and is generally configured to initiate an authentication request to the AUSF node and complete the network-side terminal authentication in an Evolved Packet System Authentication and Key Agreement (Evolved) authentication process. Packet System authentication and key agreement, EPS-AKA*).

The user plane function (UPF) node is a user plane data output and is configured to be connected to an external network.

A Data Network (DN) is a network used to provide external data, such as the Internet.

A (radio) access network (R)AN node may use different access technologies. Currently, there are two types of radio access technologies: 3GPP access technology (eg, radio access technology used in 3G, 4G or 5G system) and non-3GPP access technology. 3GPP access technology is an access technology that conforms to the specification of the 3GPP standard. The access network using 3GPP access technology is a radio access network (RAN). The network access device in the 5G system is referred to as the next generation node base station (gNB). A non-3GPP access technology is an access technology that does not comply with the 3GPP standard specification, such as a radio technology represented by a WiFi access point (AP).

The terminal device in the present invention is a device that has wireless transmission and reception functions. The terminal device may be deployed on the ground, such as an indoor device, an outdoor device, a handheld device, or a vehicle-mounted device; or can be deployed on the water (for example, on a ship); or may be deployed in the air (for example, by aircraft, balloon or satellite). The terminal device may include various types of user equipment (user equipment, UE), mobile phones (mobile phones), tablet computers (pad), computers with wireless transmission and reception functions, wireless handheld devices for data transmission, virtual reality terminal device ( virtual reality (VR), augmented reality (AR) end device, machine type communication (MTC) end device, end device in the industrial control system (industrial control), end devices in the automatic control system (self -driving), end device in the remote medical system, end device in the Smart Grid system, end device in the transport safety system, end device in the Smart City system ( Smart City), wearable devices (such as smart watches, smart bandage and pedometer) and the like. End devices that have similar wireless functionality may have different names in systems that use different radio access technologies. For ease of description, in the embodiments of the present invention, the aforementioned devices with wireless transmission and reception functions are collectively referred to as terminal devices.

In particular, the terminal device in the present invention stores a durable key and an associated function. When performing two-way authentication with a primary network node (such as an AMF node, an AUSF node, and a SEAF node), the end device can verify the network's identity using a durable key and associated function.

The network access device in embodiments of the present invention is a device that provides a wireless communication function to a terminal device. For example, the network access device may be a Base Station (BS), and the base station may include various kinds of macro base stations, micro base stations, relay stations, access points, and the like. Base station devices may have different names in systems using different radio access technologies. For example, in a 5G system, a device having the functions of a base station is referred to as a base station of a next generation node, and can be represented as a gNB; in the system of long-term development (Long Term Evolution, LTE), a device that has the functions of a base station is called an advanced NodeB (evolved NodeB, eNB or eNodeB); in a 3rd ^generation (3G) communication system, a device having the functions of a base station is referred to as a Node B. For ease of description, in the embodiments of the present invention, the aforementioned devices that provide a wireless communication function for a terminal device are collectively referred to as network access devices.

The network exposure function (NEF) node is generally configured to interoperate with a third party such that a third party can indirectly interact with a network element in some 3GPP networks.

The network function repository function (NRF) node is configured to detect the gateway element and maintain the network function (NF).

The policy control function (PCF) node stores the latest quality of service (QoS) rule. The base station may allocate an appropriate resource for the user plane transmission channel in accordance with the QoS rule provided by the SMF node.

The unified data management (UDM) node is configured to store user subscription information.

An application function node (AF) may be located within a DN and is a functional network element deployed on a third party. This network element is generally configured to notify the PCF node of the latest third party service requirements for the application. The PCF node may generate an appropriate QoS rule based on the service requirement to ensure that the service provided by the network satisfies the requirement specified by the third party.

In embodiments of the present invention, a terminal may access an AMF node using at least two access technologies. An example is considered in which at least two access technologies include a 3GPP access technology and a non-3GPP access technology. An embodiment of the present invention further provides a diagram of a possible network architecture. As shown in FIG. 2, the network architecture includes an AMF node, an AUSF node, an SMF node, a UPF node, a UDM node (or an authentication credential repository and processing function (APRF) node) ), terminal, and non-3GPP interworking function (N3IWF) node.

For AMF node, AUSF node, SMF node, UPF node, UDM node, and terminal device, see the description in FIG. 1. Details are not described here again.

The N3IWF node is configured to support the tag to access the AMF node using non-3GPP access technology.

With reference to the network architecture shown in FIG. 2, a terminal can access an AMF node using both 3GPP access technology and non-3GPP access technology. A 3GPP access technology may simply be represented as 3GPP, and a non-3GPP access technology may simply be represented as non-3GPP. Path 1 in Fig. 2 represents the path through which the terminal device accesses the AMF node through 3GPP, and path 2 represents the path through which the terminal device accesses the AMF node through non-3GPP, in other words, the terminal device can access the AMF node through N3IWF node. When an end device accesses an AMF node via 3GPP and non-3GPP, if the end device needs to send a NAS message to the AMF node, in a possible implementation the NAS message can be split into at least two message blocks, where one part of the message blocks is sent via 3GPP, and the other part of the message blocks is transmitted by non-3GPP. For example, a NAS message may be divided into message block 1, message block 2, message block 3, message block 4, and message block 5. Message blocks 2 and 4 are transmitted via 3GPP, and message blocks 1, 3 and 5 are transmitted via non-3GPP. In another possible implementation, the terminal may send the entire NAS message over 3GPP and send another full NAS message over non-3GPP.

First, terms related to embodiments of the present invention are explained.

(1) NAS COUNT

The NAS COUNT includes 24 bits, including the 16-bit NAS overflow and the 8-bit sequence number.

The initial value of NAS COUNT is 0. The uplink NAS COUNT value is incremented by 1 each time the end device sends one NAS message to the primary network device, and the downlink NAS COUNT value is incremented by 1 each time the primary network device sends one NAS message to end device. After the authentication process from the terminal device to the main network device is completed, both the uplink NAS COUNT and the downlink NAS COUNT are set to 0.

Alternatively, there are two ways to maintain NAS COUNT:

Method 1: After the NAS sends a message, the saved NAS COUNT is incremented by 1 and saved; and, when the NAS message is to be sent next time, secure the NAS message using the stored NAS COUNT.

Method 2: After the NAS message is sent, when the NAS message needs to be sent next time, the stored NAS COUNT is incremented by 1 to get a new NAS COUNT, and secure the NAS message using the new NAS COUNT.

After receiving the NAS message, the terminal device and the host network device can verify whether the received NAS COUNT should be reused, namely, verify whether the NAS COUNT transmitted in the NAS message exceeds the previously received NAS COUNT. For example, if an AMF node receives an uplink NAS COUNT from the terminal, the received uplink NAS COUNT can be compared with the previously received uplink NAS COUNT. If the received uplink NAS COUNT is larger than the previously received uplink NAS COUNT, the security check performed on the message NAS succeeds.

When encryption and decryption and integrity protection are performed using NAS COUNT, NAS COUNT is padded to 32 bits, in other words, 8 bits are padded before the original 24-bit NAS COUNT, where padding 8 bits can be all 0.

(2) Encryption and decryption

In FIG. 3 shows the process of encrypting and decrypting a NAS message.

Here, the key may be a NAS key.

The COUNT used for encryption and decryption includes 32 bits, where the first 8 bits are 0, the middle 16 bits are the NAS overflow, and the last 8 bits are the sequence number.

The channel information (BEARER) includes 5 bits and all 5 bits are 0.

Data transfer direction (DIRECTION) is used to indicate uplink or downlink. When encryption and decryption is performed for the NAS uplink message, DIRECTION indicates the uplink. When encryption and decryption is performed for a downlink message NAS, DIRECTION indicates the downlink.

The length (LENGTH) is used to specify the data length of the NAS message to be encrypted or decrypted.

The evolved packet system encryption algorithm (EEA) may be referred to as the EPS encryption algorithm and is an algorithm used to encrypt and decrypt a NAS message.

The encryption process is as follows: performing EEA processing on the input parameters (KEY, COUNT, BEARER, DIRECTION, and LENGTH) to obtain a gamma (keystream); and performing modulo 2 addition for the gamma and the plaintext (NAS message) to obtain the ciphertext (ciphertext). The decryption process is as follows: performing EEA processing based on the above input parameters to obtain gamma; and performing modulo 2 addition on the gamma and ciphertext to recover the plaintext.

(3) Integrity protection

Fig. 4 shows the process of performing integrity protection and checking the integrity protection of the NAS message.

The message (MESSAGE) is a message for which integrity protection is to be performed, and it may be, in particular, a NAS message.

An evolved packet system integrity algorithm (EPS integrity algorithm) is shown in FIG. four.

The integrity protection method is as follows: the transmitting side performs EIA processing on the input parameters (KEY, COUNT, MESSAGE, BEARER and DIRECTION) to obtain the expected message authentication code integrity (MAC-I) or NAS-MAC. The integrity protection verification method is as follows: perform EIA processing on the input parameters (KEY, COUNT, MESSAGE, BEARER, and DIRECTION) to obtain an expected message authentication code integrity (XMAC-I) or XNAS-MAC; additional comparison of XMAC-I with MAC-I; and, if the XMAC-I matches the MAC-I, determining that the integrity protection verification is successful.

The following describes in detail the technical solutions presented in the present invention.

Based on the network architectures in FIG. 1 and FIG. 2, an embodiment of the present invention provides a security method. In this method, for the encryption, decryption and integrity protection process, refer to the descriptions in FIG. 3 and FIG. 4. As shown in FIG. 5, the method basically includes step 501 and step 502.

Step 501: The terminal determines the first parameter.

The first parameter is an input parameter used when the terminal performs security for the NAS message, and the first parameter is used to specify the access technology used to transmit the NAS message. The tag may support at least two access technologies and may separately support a corresponding NAS COUNT for each of the at least two access technologies. For example, at least two access technologies comprise a 3GPP access technology and another access technology that can share the same core network device of a 3GPP network with a 3GPP access technology, such as a non-3GPP access technology or a fixed network access technology. Alternatively, that the first parameter indicates the access technology used to transmit the NAS message can be further understood as that the first parameter is used to indicate the transmission path used by the terminal to transmit the NAS message. For example, a terminal device and an AMF node may separately maintain a corresponding NAS COUNT for each transmission path without distinguishing between access technologies. If the transmission path used to transmit the NAS message is path 1, the NAS COUNT corresponding to path 1 is used. If the transmission path used to transmit the NAS message is path 2, the NAS COUNT corresponding to path 2 is used. access technologies. For example, referring to FIG. 2, the access technology used when data is transmitted on path 1 is a 3GPP access technology, and the access technology used when data is transmitted on path 2 is a non-3GPP access technology.

The first parameter may be an input parameter newly added in the encryption and decryption process or in the integrity protection process. The parameter includes the specified number of bits. Alternatively, different access technologies may be represented by setting bits to different values.

In the first possible implementation, as shown in FIG. 6, the first parameter may be an ACCESS parameter. For example, if the first parameter is 00, this indicates that the 3GPP access technology is being used; if the first parameter is 01, it indicates that a non-3GPP access technology is being used. Alternatively, 001 represents 3GPP access technology, 010 represents Wireless-Fidelity (WiFi) technology, and 011 represents fixed network technology.

Alternatively, 001 may be used to represent the first access technology used, 010 may be used to represent the second access technology used, and 011 may be used to represent the third access technology used. In other words, each time the access technology used is used, the first parameter is incremented by 1 until all bits of the first parameter are 1, and then the first parameter can be recalculated from 000. For example, if the bits of the first parameter are all changed to 1 after how the terminal repeatedly switches the used access technology when the terminal needs to switch the used access technology from the first access technology to the second access technology, the first parameter is generated for the second access technology 001. Alternatively, in this method, the first access technology, the second technology access and the third access technology may be the same technology. In other words, when the access technology is reused, the first parameter is incremented by 1 until all bits of the first parameter are 1, and then the first parameter can be recalculated from 000.

Alternatively, each time the COUNT parameter in the input parameters is reset to 0 or the NAS sequence number is reset to 0, the first parameter can also be incremented by 1.

Alternatively, when all bits of the first parameter are 1, the NAS key used when transmitting the NAS message next time must be updated.

In a second possible implementation, as shown in FIG. 7, all or some bits of the COUNT parameter in the input parameters may be used to indicate the access technology used to transmit the message to the NAS. For example, if COUNT includes 8 bits of padding with all 0s and NAS COUNT, the first parameter may be some or all of the 8 bits. For example, the first 3 bits may be chosen to indicate the access technology used to transmit the message to the NAS. To learn how to distinguish different access technologies using bit values, refer to the corresponding descriptions in the first implementation.

In a third possible implementation, as shown in FIG. 8, the BEARER parameter in the input parameters may be used to indicate the access technology used to transmit the NAS message, or to indicate the access path used to transmit the NAS message, where the first parameter may be some or all of the BEARER bits. For example, the first 3 bits may be chosen to indicate the access technology used to transmit the message to the NAS. To learn how to distinguish different access technologies using bit values, refer to the corresponding descriptions in the first implementation.

In a fourth possible implementation, the number of COUNT bits can be increased and the first parameter is some of the COUNT bits. For example, COUNT is extended from 32 bits to 64 bits (a 64-bit COUNT is adapted to a 256-bit key). The extended COUNT part is used to denote the access technology. For example, three bits are reserved to indicate an access technology, where 000 represents a 3GPP access technology, 001 represents a WiFi access technology, and 010 represents a fixed network access technology.

In a fifth possible implementation, the first parameter may be NAS COUNT and the NAS COUNT bit may be removed. The number of bits removed is used to indicate the access technology.

Alternatively, the specified number of NAS overflow bits in the existing NAS COUNT is removed and the number of removed bits is used to indicate the access technology. For example, if one bit is removed, this indicates that the access technology is a 3GPP access technology; if two bits are removed, it means that the access technology is a WiFi access technology; if three bits are removed, it means that the access technology is a fixed network access technology.

Alternatively, the predetermined number of bits of the sequence number part of the existing NAS COUNT is removed, and the number of bits removed is used to indicate the access technology. For example, if one bit is removed, this indicates that the access technology is a 3GPP access technology; if two bits are removed, it means that the access technology is a WiFi access technology; if three bits are removed, it means that the access technology is a fixed network access technology.

Alternatively, the first parameter corresponding to each access technology may be pre-configured in the terminal device. After determining the access technology used to send the NAS message, the terminal may look up the appropriate first parameter based on the access technology used to send the NAS message; or after determining the access technology used to send the NAS message, the terminal device generates the first parameter based on the access technology used to send the NAS message.

It should be noted that when the first parameter is a NAS COUNT, or the first parameter is some bits of a NAS COUNT, the end device supports different NAS COUNTs for different supported access technologies. In other cases, the end device may support the same NAS COUNT or a different NAS COUNT for different supported access technologies.

The terminal may independently determine the first parameter and notifies the AMF node of the first parameter. Alternatively, the AMF node determines the first parameter and notifies the terminal device of the first parameter. Alternatively, the first parameter may be pre-configured in the terminal device and the AMF node. For example, if the first parameter is determined by the AMF node, the terminal may receive the first parameter from the AMF node. If the first parameter is multiple bits in the NAS COUNT, after receiving the first parameter, the terminal may replace the first bit with the specified bits in the NAS COUNT stored by the terminal. Alternatively, if the first parameter is a number of bits in BEARER, the terminal may replace the specified bits in BEARER with the first parameter.

Step 502: The tag performs security for the NAS message based on the first parameter, NAS key and NAS COUNT, of the corresponding access technology used to send the NAS message.

NAS COUNT may be a parameter that has a function to prevent NAS message replay attack. A NAS key is a NAS key used by at least two access technologies that may be supported by the end device.

That the terminal performs security on the NAS message indicates: encrypting the NAS message to be transmitted to the primary network device, decrypting the received NAS message, and performing integrity protection of the NAS message to be transmitted to the primary network device, or performing a security check the integrity of the received NAS message. Accordingly, the key used to perform the security of the NAS message may be an encryption key and an integrity protection key. In this embodiment of the present invention, the encryption key and the integrity protection key are collectively referred to as NAS keys. The sequence of performing encryption, decryption, product integrity protection, and integrity protection verification is not limited in this embodiment of the present invention.

It may be appreciated that a terminal may support a corresponding NAS COUNT for each of the at least two access technologies. If the terminal transmits a NAS message using 3GPP access technology, security is performed for the NAS message using the first parameter corresponding to the 3GPP access technology, the uplink NAS COUNT supported by the terminal for the 3GPP access technology, and the NAS key.

According to the three implementations of the first parameter, the methods for encrypting the NAS message are shown separately in FIG. 6, fig. 7 and FIG. eight.

According to the above first embodiment with reference to FIG. 4, the input parameter used when the NAS security message is performed can also be used.

According to the above second implementation with reference to FIG. 4, COUNT in the input parameter used in performing NAS security of the message includes the first parameter.

According to the above third implementation with reference to FIG. 4, BEARER in the input parameter used in performing NAS security of the message includes the first parameter.

Alternatively, if the terminal device receives the NAS message, the terminal device may determine the first parameter corresponding to the access technology used to transmit the NAS message in order to decrypt and/or perform a NAS message integrity check using the downlink NAS COUNT transmitted to the NAS. message, the first parameter corresponds to the access technology used to send the message to the NAS and the NAS key.

According to the security method provided in this embodiment of the present invention, a terminal can separately maintain a corresponding NAS COUNT for each of at least two access technologies. An end device does not use the same set of NAS COUNTs when transmitting a NAS message using different access technologies. Instead, the end device performs security for the NAS message with the NAS COUNT supported for the corresponding access technology. This can prevent a replay attack that occurs when the underlying network device first receives a relatively small NAS COUNT transmitted on one link and then receives a relatively large NAS COUNT transmitted on another link. In the present invention, the first parameter used to distinguish between different access technologies is further used when message protection is performed on the NAS message. Therefore, even if the same NAS key and the same NAS COUNT are used, when security is performed on a NAS message transmitted using different access technologies, the results of protecting the NAS message are different, which reduces the possibility of occurrence of a replay attack, thereby , realizing security for multiple NAS connection lines.

In accordance with the embodiment in FIG. 5, a method for securing a NAS message by a main network device is further provided in another implementation of this embodiment of the present invention. The underlying network device may be an AMF node, a SEAF node, an MME node, a node involved in the end device authentication process, or another node associated with key generation and key storage. In this embodiment of the present invention, that the main network device is an AMF node is used as an example. As shown in FIG. 9, the method includes the following steps.

Step 901: The AMF node determines the first parameter.

The first parameter is used to specify the access technology used to send the message to the NAS. The AMF node may separately maintain a corresponding NAS COUNT for each of the at least two access technologies supported by the end device.

The method for determining the first AMF parameter by the node is similar to the method for determining the first parameter by the terminal in step 501 in FIG. 5 and reference can be made to the corresponding description at 501.

Step 902: The AMF node performs security for the NAS message based on the first parameter, NAS key and NAS COUNT corresponding to the access technology used to transmit the NAS message.

NAS COUNT may be a parameter that has a function to prevent NAS message replay attack.

What the AMF node performs protection for the NAS message may be: encrypting the NAS message to be transmitted to the end device, decrypting the received NAS message, and performing integrity protection of the NAS message to be transmitted to the end device, or performing an integrity protection check received NAS message.

The manner in which a node performs NAS security of an AMF message is similar to the manner in which a terminal device performs security of an NAS message in step 502, and reference can be made to the corresponding description in step 502.

According to the security method provided in this embodiment of the present invention, the underlying network device can separately maintain a corresponding NAS COUNT for each of the at least two access technologies. An end device does not use the same set of NAS COUNTs when transmitting a NAS message using different access technologies. Instead, the end device secures the NAS message with the NAS COUNT supported for the corresponding access technology. This can prevent a replay attack that occurs when the underlying network device first receives a relatively small NAS COUNT transmitted on one link and then receives a relatively large NAS COUNT transmitted on another link. In the present invention, the first parameter used to distinguish between different access technologies is further used when message protection is performed on the NAS message. Therefore, even if the same NAS key and the same NAS COUNT are used, when security is performed on a NAS message transmitted using different access technologies, the results of protecting the NAS message are different, which reduces the possibility of occurrence of a replay attack, thereby , realizing security for multiple NAS connection lines.

Alternatively, if the access technology used to transmit the NAS message is the first access technology, before the procedures in FIG. 5 and FIG. 9 as shown in FIG. 10, the method may further include steps 1001-1007.

Step 1001: The terminal device determines the first uplink NAS COUNT corresponding to the first access technology.

The first uplink NAS COUNT is 0, and in particular, all or some bits of the first uplink NAS COUNT are 0.

Alternatively, the first uplink NAS COUNT is a random number. In particular, some or all of the bits in the first uplink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part in the first uplink NAS COUNT is a random number. In this case, the remainder is 0.

Alternatively, the at least two access technologies further include a second access technology, and the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the second access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the second access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that corresponds to the second access technology and is stored by the terminal.

Alternatively, the at least two access technologies further include a second access technology, and the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the second access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the second access technology, the first uplink NAS COUNT is the sum of 1 and the largest uplink NAS COUNT that corresponds to the second access technology and that is stored by the terminal.

Alternatively, the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the first access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the first access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that corresponds to the first access technology and is stored by the terminal.

Alternatively, the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the first access technology and that is stored by the terminal. If the terminal stores at least two uplink NAS COUNTs corresponding to the first access technology, the first uplink NAS COUNT is the sum of 1 and the largest uplink NAS COUNT that corresponds to the first access technology and is stored by the terminal.

Alternatively, the first access technology and the second access technology may be separately a 3GPP access technology, a non-3GPP access technology, a fixed network access technology, another technology that can be used to access the underlying network device, or any technology that can be combined. use a 3GPP core network device with 3GPP access technology. In this embodiment of the present invention, an example is used for description in which the first access technology is a non-3GPP access technology and the second access technology is a 3GPP access technology.

Obviously, before a tag sends a NAS message to an AMF node using a non-3GPP access technology, the tag needs to determine the first uplink NAS COUNT transmitted when the NAS message is sent via the non-3GPP access technology.

If a terminal accesses an AMF node using a non-3GPP access technology for the first time, the first uplink NAS COUNT corresponding to the non-3GPP access technology may be set to 0 or a random number. Alternatively, when the terminal device has accessed the AMF node through 3GPP access technology, if the NAS COUNT service method is method 1 described above (after the NAS message is sent, the NAS COUNT used in the NAS message is incremented by 1 and stored, and when the NAS message is needed send the next time security is performed for the NAS message using the stored NAS COUNT), it can be determined that the first uplink NAS COUNT is an uplink NAS COUNT that conforms to the 3GPP access technology that is stored in the terminal. If the terminal device stores at least two uplink NAS COUNTs conforming to 3GPP access technology and the terminal device cannot determine the uplink NAS COUNT used by the previous NAS message, the largest uplink NAS COUNT that complies with 3GPP is selected. access technology and which is stored by the end device, and security is performed for the NAS message. If the NAS COUNT service method is method 2 above (after the NAS message is sent, when the NAS message needs to be sent next time, the saved NAS COUNT is incremented by 1 to determine a new NAS COUNT, and security is performed for the NAS message with using the new NAS COUNT), it can be determined that the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that conforms to the 3GPP access technology and that is stored by the terminal. If the terminal device stores at least two uplink NAS COUNTs conforming to 3GPP access technology, and the terminal device cannot determine the uplink NAS COUNT used by the previous NAS message, select the largest uplink NAS COUNT that complies with 3GPP access technology and which is stored by the terminal and incremented by 1 and security is performed for the NAS message using the uplink NAS COUNT incremented by 1.

When a terminal device accesses an AMF node through a non-3GPP access technology, if the NAS COUNT service method is the above method 1, it can be determined that the first uplink NAS COUNT is an uplink NAS COUNT that corresponds to the non-3GPP access technology. , which is stored by the end device; or, if the NAS COUNT serving method is the above method 2, it may be determined that the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that corresponds to the non-3GPP access technology and that is stored by the terminal.

Step 1002: The terminal sends a first AMF message to the node, where the first message carries some or all of the bits of the first uplink NAS COUNT.

Security is performed for the first message using the first uplink NAS COUNT and the NAS key. Alternatively, the first message may carry the 24-bit uplink first COUNT, or may only carry some bits of the first uplink COUNT, eg, only carry the last 4 or 8 bits of the first uplink NAS COUNT.

In another possible implementation, if the terminal device accesses the AMF node for the first time through a non-3GPP access technology, and the terminal device has accessed the AMF node through the 3GPP access technology, the terminal device may temporarily not determine the first uplink NAS COUNT and perform security first of all for the first message using NAS COUNT corresponding to non-3GPP access technology, in other words, step 1001 and step 1002 can be replaced by step 1003.

Step 1003: The tag sends a first AMF message to the node, where the first message carries some or all of the uplink NAS COUNT bits corresponding to the second access technology.

The first message is secured using the NAS key and the uplink NAS COUNT corresponding to the second access technology.

The uplink NAS COUNT that corresponds to the second access technology and that is carried in the first message is some or all of the bits of the uplink NAS COUNT that corresponds to the second access technology and that is stored by the terminal, or is some or all of the bits of the new uplink NAS COUNTs uplink NAS COUNTs received after the uplink NAS COUNT that correspond to the second access technology and which are stored by the terminal device are increased by 1. If the terminal device stores at least two uplink NAS COUNTs corresponding to the second access technology, the uplink NAS COUNT link corresponding to the second access technology at this stage is the largest uplink NAS COUNT that corresponds to the second access technology and which is stored by the terminal device.

Note that, Optionally, the first message in step 1002 and step 1003 both include first indication information, where the first indication information is used to indicate an access technology corresponding to some or all of the uplink NAS COUNT bits transmitted in the first message, or the first indication information is used to indicate the transmission path corresponding to some or all of the bits of the NAS COUNT transmitted in the first message. For example, the first indication information transmitted in the first message at step 1002 indicates a non-3GPP access technology, and the first indication information transmitted in the first message at step 1003 indicates a 3GPP access technology. In another example, the first indication information transmitted in the first message at step 1002 indicates access to the AMF node via path 1, and the first indication information transmitted in the first message at step 1003 indicates access to the AMF node via path 2.

The following steps may be additionally performed after step 1002 or step 1003.

Step 1004: The AMF node receives the first message.

Step 1005: The AMF node checks, based on the uplink NAS COUNT corresponding to the access technology indicated in the first indication information, the NAS COUNT transmitted in the first message.

The indication information may be an explicit indication or may be an implicit notification. For example, the access type information may be access type indication information (such as a radio access technology (RAT) type access type) that is explicitly indicated in the N2 message, or is access type indication information that is added in the NAS message. The AMF node may determine the access type based on the source of the first message when there is no access type indication information. For example, if the message source address is a base station, the access type is 3GPP access; if the message source address is an N3IWF node, the access type is non-3GPP access; if the source address of the message is a device connected to a fixed network, the access type is fixed network access.

When the first indication information indicates a non-3GPP access technology, if the first message transmits the full first NAS COUNT and the AMF node determines that the terminal device has accessed the AMF node, the AMF node determines whether the first NAS COUNT is larger than the previously received An uplink NAS COUNT that conforms to the non-3GPP access technology and that is maintained by the AMF node. If the first NAS COUNT is greater than the previously received uplink NAS COUNT, authentication succeeds; or, if the first NAS COUNT is less than the previously received uplink NAS COUNT, authentication fails, access to the tag is denied, and the tag is informed of the reason for the failure. Alternatively, if the AMF node determines that the terminal has not accessed the AMF node using a non-3GPP access technology, the AMF node stores the first NAS COUNT as the uplink NAS COUNT corresponding to the non-3GPP access technology, or the AMF node determines that the uplink NAS COUNT value corresponding to the non-3GPP access technology is 0. If the first message contains part of the first NAS COUNT, the AMF node first recovers the complete first NAS COUNT, and then checks or stores the first NAS COUNT according to the above processing method first NAS COUNT.

When the first indication information indicates a 3GPP access technology, if the first message contains a complete NAS COUNT corresponding to the 3GPP access technology, the AMF node determines whether the first NAS COUNT is larger than the previously received uplink NAS COUNT that corresponds to the 3GPP access technology and is stored by the AMF node. . If the first NAS COUNT is greater than the previously received uplink NAS COUNT, the test succeeds; or, if the first NAS COUNT is less than the previously received uplink NAS COUNT, the authentication fails. If the first message contains a part of the NAS COUNT corresponding to the 3GPP access technology, the AMF node first recovers the full NAS COUNT, and then checks the recovered full NAS COUNT using the NAS COUNT verification method described above.

Step 1006: The AMF node determines one or both of the second uplink NAS COUNT and the first downlink NAS COUNT that correspond to the first access technology.

The second uplink NAS COUNT is 0, and specifically, all or some bits of the second uplink NAS COUNT are 0. Alternatively, the second uplink NAS COUNT is a random number. In particular, some or all of the bits in the second uplink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part of the second uplink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the second uplink NAS COUNT is a downlink NAS COUNT that corresponds to the second access technology and that is stored by the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the second uplink NAS COUNT is the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the second access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the second access technology and which is stored in the main network device. Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the first access technology and which is stored in the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the first access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the first access technology and which is stored by the core network device. Alternatively, the second uplink NAS COUNT is the first uplink NAS COUNT; or the second uplink NAS COUNT is the sum of 1 and the first uplink NAS COUNT.

Alternatively, if the first message received by the AMF node contains the first uplink NAS COUNT, the AMF node may determine that the second uplink NAS COUNT is the first uplink NAS COUNT, or that the second uplink NAS COUNT is the sum of 1 and the first uplink NAS COUNT.

Alternatively, if the first message received by the AMF node contains the first uplink NAS COUNT, this indicates that the terminal has determined the NAS COUNT corresponding to the non-3GPP access technology, and the AMF node may not determine the second NAS COUNT.

The first downlink NAS COUNT is 0, and in particular, all or some bits of the first downlink NAS COUNT are 0.

Alternatively, the first downlink NAS COUNT is a random number. In particular, some or all of the bits in the first downlink NAS COUNT are random numbers. For example, the sequence number part or the NAS overflow part in the first uplink NAS COUNT is a random number. In this case, the remainder is 0. Alternatively, the first downlink NAS COUNT is a downlink NAS COUNT which corresponds to the second access technology and which is stored in the main network device. If the core network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the first downlink NAS COUNT is the largest downlink NAS COUNT that corresponds to the second access technology and is stored by the core network device. Alternatively, the first downlink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the second access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the second access technology, the first downlink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the second access technology and which is stored primarily network device. Alternatively, the first downlink NAS COUNT is the sum of 1 and the downlink NAS COUNT which corresponds to the first access technology and which is stored in the main network device. If the underlying network device stores at least two downlink NAS COUNTs corresponding to the first access technology, the first downlink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the first access technology and which is stored mainly network device.

Alternatively, if the first message received by the AMF node contains a NAS COUNT corresponding to the second access technology, the second uplink NAS COUNT determined by the AMF node may be the same as the first downlink NAS COUNT.

Step 1007: The AMF node sends a second message to the tag, where the second message includes one or both of the second uplink NAS COUNT and the first downlink NAS COUNT that correspond to the first access technology.

Accordingly, the terminal device receives the second message.

Alternatively, the second message contains the second indication information, and the second indication information is used to indicate the access technology corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information used to indicate the second uplink NAS COUNT transmitted in the second message. Alternatively, the second indication information is used to indicate the transmission path corresponding to the first downlink NAS COUNT transmitted in the second message. Alternatively, the second message may further comprise indication information that is used to indicate a transmission path corresponding to the second uplink NAS COUNT transmitted in the second message. It is understood that since the second message contains the first downlink NAS COUNT corresponding to the first access technology, the second indication information is used to indicate the first access technology. For example, if the first access technology is a 3GPP access technology, the second indication information is used to indicate the 3GPP access technology; if the first access technology is a non-3GPP access technology, the second indication information is used to indicate the non-3GPP access technology.

Obviously, after receiving the second message, the terminal may store one or both of the second uplink NAS COUNT and the first downlink NAS COUNT that are carried in the second message. When the next time it is necessary to send an uplink message to the NAS via non-3GPP, security for the NAS message can be performed based on the second uplink NAS COUNT. Alternatively, after receiving the downlink message by the NAS, the downlink NAS COUNT in the received downlink message by the NAS may be checked based on the first downlink NAS COUNT.

With reference to a specific scenario, the security method described in the previous embodiments is described below. An embodiment of the present invention can be applied to a scenario in which a terminal has accessed an AMF node using 3GPP access technology, and then the terminal has accessed the same AMF node using non-3GPP access technology. Fig. 11A and FIG. 11B show a registration process in which a terminal accesses an AMF node using a non-3GPP access technology. The method includes the following steps.

Step 1101: The tag accesses an untrusted non-3GPP network.

For example, the end device accesses a WiFi network that cannot be directly trusted.

At this point, the end device is accessing an untrusted non-3GPP network, and the end device has been authenticated by the 3GPP network and has a NAS security context. The NAS security context includes a NAS key, a key ID, and a NAS COUNT corresponding to 3GPP access technologies. Alternatively, the NAS context further includes a NAS COUNT corresponding to a non-3GPP access technology. If the terminal has accessed the AMF node through a non-3GPP access technology, the NAS COUNT corresponding to the non-3GPP access technology is not equal to 0. If the end device has not accessed the AMF node through a non-3GPP access technology, the NAS COUNT corresponding to the non -3GPP access technology is 0.

The NAS key may be one or both of an encryption key and an integrity protection key.

Step 1102: The terminal exchanges an internet key exchange protocol security association initial (IKE_SA_INIT) protocol initial message with the N3IWF node.

The IKE_SA_INIT message contains a key material, and the key material is information used to perform security on a message sent between an end device and an N3IWF node. After the terminal exchanges an IKE_SA_INIT message with the N3IWF node, the terminal and the N3IWF node may generate the same key, and this key is used to perform security on the message subsequently sent by the terminal and the N3IWF node.

Step 1103: The terminal sends an Internet key exchange protocol authentication request (IKE_AUTH_Req) message to the N3IWF node.

Accordingly, the N3IWF node receives an IKE_AUTH_Req message.

Step 1104: The N3IWF node sends an Internet key exchange protocol authentication response (IKE_AUTH_Res) authentication response message to the terminal.

Accordingly, the tag receives an IKE_AUTH_Res message.

The IKE_AUTH_Res message contains a 5G start message (extensible authentication protocol _5 ^th generation_request, EAP_5G_Req) message, and an EAP_5G_Req message is used to request the end device to start the extensible authentication protocol (EAP) procedure. .

Step 1105: The tag determines the first uplink NAS COUNT.

The first uplink NAS COUNT is the COUNT used to perform NAS security on the message sent by the AMF terminal to the node.

There are two implementations of this stage.

In the first implementation, the terminal device determines the first uplink NAS COUNT based on the uplink NAS COUNT corresponding to the 3GPP access technology.

Since the terminal device has accessed the AMF node through the 3GPP access technology, the terminal device has stored the NAS COUNT corresponding to the 3GPP access technology. If the service method of the NAS COUNT is the above method 1, then it can be determined that the first uplink NAS COUNT is an uplink NAS COUNT that conforms to the 3GPP access technology and that is stored by the terminal (if the terminal stores at least two NAS uplink COUNTs corresponding to the 3GPP access technology, the first uplink NAS COUNT is the largest uplink NAS COUNT that conforms to the 3GPP access technology and is stored by the terminal). If the service method of the NAS COUNT is the above method 2, then it can be determined that the first uplink NAS COUNT is the sum of 1 and the uplink NAS COUNT that conforms to the non-3GPP access technology and that is stored by the terminal (if the terminal stores, at least two uplink NAS COUNTs corresponding to the non-3GPP access technology, the first uplink NAS COUNT being the sum of 1 and the largest uplink NAS COUNT that corresponds to the non-3GPP access technology and which is stored by the terminal).

In the second implementation, the terminal generates a NAS COUNT corresponding to a non-3GPP access technology and uses as a first uplink NAS COUNT, a NAS COUNT corresponding to a non-3GPP access technology.

Alternatively, if the terminal has accessed the AMF node via a non-3GPP access technology, the terminal may determine that the first uplink NAS COUNT is an uplink NAS COUNT that conforms to the non-3GPP access technology and that is stored by the terminal. (if the terminal stores at least two non-3GPP access technology uplink NAS COUNTs, the first uplink NAS COUNT is the largest uplink NAS COUNT that conforms to the non-3GPP access technology and that is stored by terminal) or the terminal may determine that the first uplink NAS COUNT is the sum of 1 and a NAS COUNT that conforms to the non-3GPP access technology and that is stored by the terminal (if the terminal stores at least two uplink NAS COUNTs communications conforming to non-3GPP technology access policy, the first uplink NAS COUNT is the sum of 1 and the highest uplink NAS COUNT that complies with the non-3GPP access technology and that is stored by the terminal).

Alternatively, if the first uplink NAS COUNT is determined in the second implementation, during the registration process in which the terminal device accesses the AMF node using non-3GPP access technology, the terminal device does not send a message to the NAS using 3GPP access technology.

Alternatively, the terminal may additionally install an indicator. The indicator is equivalent to the first indication information in the embodiment corresponding to FIG. 10 and is used to indicate whether the first uplink NAS COUNT conforms to a 3GPP access technology or a non-3GPP access technology. It should be understood that if the terminal determines the first uplink NAS COUNT in the above first implementation, the indicator indicates the 3GPP access technology; or, if the terminal determines the first uplink NAS COUNT in the above second implementation, the indicator indicates a non-3GPP access technology.

Step 1106: The tag sends an IKE_AUTH_Req message to the N3IWF node.

Accordingly, the N3IWF node receives an IKE_AUTH_Req message.

The IKE_AUTH Req message includes a NAS protocol data unit (PDU) and an extended authentication protocol for transporting a non-access layer 5G message (5G-NAS message corresponding to the EAP_5G_ReS message) or 5G-NAS message. The NAS PDU includes a registration request message. The registration request message is used by the terminal to register with the AMF node using the 3GPP access technology. Alternatively, the first message in the above embodiment may be a registration request message.

Alternatively, integrity protection may be performed on the registration request message using the first uplink NAS COUNT, and the registration request message includes the first indication information and the first uplink NAS COUNT. Alternatively, the registration request message further includes a key identifier and a temporary terminal identifier.

Step 1107: The N3IWF node selects an AMF node.

Refer to the prior art for the method of selecting an AMF node by an N3IWF node.

Step 1108: The N3IWF node forwards a registration request message to the AMF node.

Accordingly, the AMF node receives a registration request message.

Step 1109: The AMF node verifies the registration request message.

The verification performed in the AMF Registration Request message by the node includes an integrity protection check performed in the Registration Request message and a verification performed in the first uplink NAS COUNT carried in the Registration Request message. That the AMF node verifies the first uplink NAS COUNT carried in the registration request message corresponds to the previous step 1005.

The AMF node may generate an integrity protection key based on the temporary identifier and the key identifier in the registration request message, and perform an integrity protection check in the registration request message based on the integrity protection key.

If the access technology that corresponds to the first uplink NAS message and that is indicated in the first indication information is a 3GPP access technology, the AMF node verifies whether the first uplink NAS COUNT is larger than the previously received NAS COUNT corresponding to the 3GPP access technology. If the first uplink NAS COUNT is greater than the previously received NAS COUNT, then verification is successful; or, if the first uplink NAS COUNT is not greater than the previously received NAS COUNT, then verification is not performed.

If the access technology that corresponds to the first uplink NAS message and that is indicated by the first indication information is a non-3GPP access technology, and the terminal has not accessed the AMF node via the non-3GPP access technology, the AMF node stores the first NAS COUNT as The uplink NAS COUNT corresponding to the non-3GPP access technology or AMF node determines that the uplink NAS COUNT corresponding to the non-3GPP access technology is 0. The terminal has accessed the AMF node through the non-3GPP access technology. The AMF node verifies if the first uplink NAS COUNT is larger than the previously received NAS COUNT corresponding to the non-3GPP access technology. If the first uplink NAS COUNT is greater than the previously received NAS COUNT, verification is successful; or, if the first uplink NAS COUNT is not greater than the previously received NAS COUNT, then verification is not performed.

Step 1110: The AMF node generates a key Kn3iwf for the N3IWF node.

The Kn3iwf key is used for two-way authentication between the AMF node and end device.

Step 1111: The AMF node determines one or both of the second uplink NAS COUNT and the first downlink NAS COUNT that conform to the non-3GPP access technology.

Alternatively, if the access technology indicated by the first indication information is a 3GPP access technology, this indicates that the terminal device does not define a NAS COUNT for a non-3GPP access technology, and the AMF node can determine the second uplink NAS COUNT and the first NAS COUNT downlink that conform to non-3GPP access technologies. If the access technology specified in the first indication information is a non-3GPP access technology, this indicates that the terminal device determines the uplink NAS COUNT for the non-3GPP access technology and the AMF node only needs to determine the first corresponding downlink NAS COUNT for the non-3GPP access technology. The -3GPP technology or AMF node determines the first downlink NAS COUNT and overrides the non-3GPP access technology uplink NAS COUNT.

Specifically, the second uplink NAS COUNT is 0, or the second uplink NAS COUNT is a random number.

If the second uplink NAS COUNT is 0, all or some bits of the second uplink NAS COUNT are 0. If the second uplink NAS COUNT is a random number, some or all of the bits in the second uplink NAS COUNT are random numbers. For example, the last 8 bits (sequence number part) of the second uplink NAS COUNT are random numbers, or the NAS overflow part is a random number, and the remaining part is 0. Alternatively, if the second uplink NAS COUNT is random Second , the uplink NAS COUNT must be greater than the downlink NAS COUNT that conforms to the 3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs conforming to the 3GPP access technology, the second The uplink NAS COUNT must be greater than the largest downlink NAS COUNT that complies with the 3GPP access technology and that is stored by the AMF node).

The second uplink NAS COUNT may be a downlink NAS COUNT that conforms to the 3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs conforming to the 3GPP access technology, the second uplink NAS COUNT link is the largest downlink NAS COUNT that conforms to the 3GPP access technology and is stored in the terminal). Alternatively, the second uplink NAS COUNT is the sum of 1 and the downlink NAS COUNT that complies with the 3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs conforming to 3GPP access technology, the second uplink NAS COUNT is the sum of 1 and the highest downlink NAS COUNT that conforms to the 3GPP access technology and is stored by the terminal). Alternatively, the second uplink NAS COUNT may be the sum of 1 and a downlink NAS COUNT that conforms to the non-3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs corresponding to non-3GPP access technology, the second uplink NAS COUNT is the sum of 1 and the largest downlink NAS COUNT that corresponds to the non-3GPP access technology and is stored by the terminal). Alternatively, the second uplink NAS COUNT is the first uplink NAS COUNT; or the second uplink NAS COUNT is the sum of 1 and the first uplink NAS COUNT.

Alternatively, the first downlink NAS COUNT may be the same as the second uplink NAS COUNT.

In particular, the first downlink NAS COUNT may be 0 or may be a random number.

If the first downlink NAS COUNT is 0, then all or some bits of the first downlink NAS COUNT are 0. If the first downlink NAS COUNT is a random number, some or all of the bits in the first downlink NAS COUNT are random numbers. For example, the last 8 bits (sequence number part) of the first downlink NAS COUNT are random numbers, or the NAS overflow part is a random number and the remainder is 0. Alternatively, if the first downlink NAS COUNT is random. First, the NAS COUNT of the first downlink must be greater than the NAS COUNT of the downlink which conforms to the 3GPP access technology and which is maintained by the AMF node.

Alternatively, the first downlink NAS COUNT may be a downlink NAS COUNT that complies with the 3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs corresponding to the 3GPP access technology first The downlink NAS COUNT may further be the largest downlink NAS COUNT that complies with the 3GPP access technology and that is maintained by the AMF node). Alternatively, the first downlink NAS COUNT may be the sum of 1 and a downlink NAS COUNT that conforms to the 3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs conforming to the 3GPP access technology , the first downlink NAS COUNT may further have a sum of 1 and the largest downlink NAS COUNT that conforms to the 3GPP access technology and that is maintained by the AMF node). Alternatively, the first downlink NAS COUNT may be the sum of 1 and a downlink NAS COUNT that conforms to a non-3GPP access technology and that is stored by the AMF node (if the AMF node stores at least two downlink NAS COUNTs corresponding to non -3GPP access technology, the first downlink NAS COUNT may further be the sum of 1 and the largest downlink NAS COUNT that corresponds to the non-3GPP access technology and which is maintained by the AMF node).

It should be noted that the AMF node may store one or both of the generated second uplink NAS COUNT and the generated first downlink NAS COUNT. The AMF node may support uplink NAS COUNT and downlink NAS COUNT that conform to 3GPP access technology, and may further support uplink NAS COUNT and downlink NAS COUNT that conform to non-3GPP access technology. If the AMF node generates the second uplink NAS COUNT and the first downlink NAS COUNT, the AMF node stores the second uplink NAS COUNT and the first downlink NAS COUNT. If the AMF node generates only the first downlink NAS COUNT, the AMF node stores the first downlink NAS COUNT. In this case, the uplink NAS COUNT that conforms to the non-3GPP access technology and that is supported by the terminal device is the first uplink NAS COUNT.

Obviously, the AMF node separately maintains a set of NAS COUNTs for each of the 3GPP access technology and non-3GPP access technology, in other words, the NAS COUNTs maintained by the AMF node for the 3GPP access technology and the NAS COUNTs supported by the AMF node for the non-3GPP technology access do not affect each other. When the NAS receives the AMF uplink message, the node can determine, based on the bit information in the uplink NAS message or the information in the N2 message, the access technology or transmission path used by the terminal to transmit the uplink message to the NAS. If the access technology used is the 3GPP access technology, the uplink NAS COUNT carried in the uplink NAS message can be compared to the largest uplink NAS COUNT supported for the 3GPP access technology. If the access technology used is a non-3GPP access technology, then the uplink NAS COUNT carried in the uplink NAS message can be compared with the largest uplink NAS COUNT supported for the non-3GPP access technology to prevent replay attack.

Step 1112: The AMF node sends a security mode command (SMC) message to the NAS using the node's N3IWF.

Accordingly, the end device receives the NAS SMC message.

The second message in the above embodiment may be a NAS SMC message.

The NAS SMC message conveys one or both of the second uplink NAS COUNT and the first downlink NAS COUNT. It is understood that if the AMF node determines only the first downlink NAS COUNT, the NAS SMC message transmits the first downlink NAS COUNT. If the AMF node specifies a second uplink NAS COUNT and a first downlink NAS COUNT, the NAS SMC message contains the second uplink NAS COUNT and the first downlink NAS COUNT.

Alternatively, if the NAS message only transmits the first downlink NAS COUNT, the NAS message may further contain indication information used to instruct the terminal device to continue using the uplink NAS COUNT determined by the terminal device.

Alternatively, the NAS SMC message further includes second indication information, and the second indication information is used to indicate the access technology or transmission path corresponding to the NAS COUNT transmitted in the NAS SMC message. In the scenario of this embodiment, the access technology indicated by the second indication information is a non-3GPP access technology.

Step 1113: The tag determines, based on the NAS SMC message, an uplink NAS COUNT and a downlink NAS COUNT that conform to the non-3GPP access technology.

The terminal may separately maintain a set of NAS COUNTs for each of the 3GPP access technology and non-3GPP access technology. In the scenario of this embodiment, the tag has stored the uplink NAS COUNT and the downlink NAS COUNT that conform to the 3GPP access technology, and the tag can further determine, based on the NAS SMC message received in this step, the uplink NAS COUNT and the NAS Downlink COUNTs that are supported for non-3GPP .

Alternatively, if the NAS SMC message only includes the first downlink NAS COUNT, the terminal determines that the uplink NAS COUNT corresponding to the non-3GPP access technology is still the first uplink NAS COUNT and the downlink NAS COUNT link corresponding to non-3GPP access technology, is the first NAS COUNT downlink. If the NAS SMC message includes a second uplink NAS COUNT and a first downlink NAS COUNT, the terminal may determine that the uplink NAS COUNT corresponding to the non-3GPP access technology is the second uplink NAS COUNT, NAS COUNT downlink corresponding to non-3GPP access technology, is the first downlink NAS COUNT.

Obviously, upon receiving the NAS downlink message, the tag can determine, based on the information bits in the NAS downlink message, the access technology or transmission path used by the tag to send the NAS downlink message. If the access technology used is a 3GPP access technology, the downlink NAS COUNT carried in the NAS downlink message can be compared to the largest downlink NAS COUNT supported for the 3GPP access technology. If the access technology used is a non-3GPP access technology, then the downlink NAS COUNT carried in the downlink NAS message can be compared to the largest downlink NAS COUNT supported for the non-3GPP access technology to prevent replay attack.

Step 1114: The tag sends an AMF security mode complete (SMP) message to the NAS using the node's N3IWF.

Accordingly, the AMF node receives the NAS SMC message.

Alternatively, the NAS message at step 502 may be a NAS SMC message at this step.

The end device may perform integrity protection for the NAS SMC message using the first parameter, the uplink NAS COUNT and the NAS key. The first parameter is used to indicate that the access technology used to transmit the message to the NAS SMC is a non-3GPP access technology, or is used to indicate that the transmission path used to transmit the message to the NAS SMC is path 2 in FIG. 2. The uplink NAS COUNT is the uplink NAS COUNT that conforms to the non-3GPP access technology and is determined by the terminal in step 1113, or the uplink NAS COUNT corresponding to path 2. The SMC NAS message contains the uplink NAS COUNT .

It may be appreciated that after receiving the NAS SMC AMF message, the node can check whether the uplink NAS COUNT carried in the NAS SMC message is larger than the uplink NAS COUNT that conforms to the non-3GPP access technology, and that the AMF is stored by the node, or the value that the uplink NAS COUNT carried in the NAS SMC message is greater than the uplink NAS COUNT corresponding to path 2. If the uplink NAS COUNT value carried in the NAS SMC message is greater than the uplink NAS COUNT which conforms to the non-3GPP access technology and which is held by the AMF node, or the uplink NAS COUNT carried in the NAS SMC message is greater than the uplink NAS COUNT corresponding to path 2 can be determined based on the bit information in NAS message that the access technology used to send the NAS SMC message is a non-3GPP access technology to determine Enter the first parameter corresponding to the non-3GPP access technology, and then perform an integrity check on the information of the NAS SMC message based on the first parameter, the NAS key and the uplink NAS COUNT carried in the NAS SMC message. If the check is successful, then step 1115 is executed. Alternatively, if the AMF stores a plurality of uplink NAS COUNTs, it may be checked whether the uplink NAS COUNT carried in the NAS SMC message is greater than the largest uplink NAS COUNT , which conforms to the non-3GPP access technology and which is maintained by the AMF node.

Step 1115: The AMF node sends an N2 message to the N3IWF node. The N2 message contains the key Kn3iwf and a registration completion message.

Accordingly, the N3IWF node receives the N2 message.

Step 1116: The N3IWF node sends an EAP-5G-Success message to the terminal.

Accordingly, the terminal receives the EAP-5G-Success message.

Step 1117: The terminal device and the N3IWF node complete the calculation of the authentication parameter (authentication) using Kn3iwf.

Step 1118: An Internet protocol security (IPsec) connection is established between the terminal and the N3IWF node.

Step 1119: The N3IWF node sends a registration complete message to the terminal.

According to the method provided in this embodiment of the present invention, a terminal device can access the network through non-3GPP access technology, and can independently support NAS COUNT for 3GPP access technology and NAS COUNT for non-3GPP access technology, thereby reducing the possibility of repetition attacks.

In an exemplary implementation of this embodiment of the present invention, a terminal's security context may be tied to operator information. For example, the operator information may be a PLMN identifier. After the terminal device accesses the network using the 3GPP access technology provided by operator A, when the terminal device performs the procedure corresponding to FIG. 11A and FIG. 11B, it can be determined whether the N3IWF node corresponding to the non-3GPP access technology is still operator A. If the N3IWF node is still operator A, the procedure corresponding to FIG. 11A and FIG. 11B can be continued.

In another possible implementation, the security context of the terminal on the side of the non-3GPP access technology may be associated with other information such as subscription information and location area information. For example, a terminal device moves from the coverage area of base station A to the coverage area of base station B, the coverage area of base station A supports non-3GPP access technology C, and base station B supports non-3GPP access technology D. If the terminal device accesses the network through non-3GPP access technology C, when a terminal device moves from the coverage area of base station A to the coverage area of base station B, if the subscription information of the terminal device indicates that the terminal device cannot have permission to use non-3GPP access technology D, the terminal the device cannot access the network through non-3GPP access technology D.

Alternatively, in the foregoing AMF embodiment, the node may determine, based on the first indication information, the access technology used to transmit the NAS message. This embodiment of the present invention further provides three methods for determining the access technology used to transmit the N2 message or NAS message after the AMF node receives the N2 message.

Method 1: The AMF node may determine, based on the source N2 of the message, the access technology used to send the N2 message. For example, the AMF node determines the source of the message based on the source address information (eg, IP address) and further determines, based on the source of the message, the access technology used to send the message. If the N2 message is received from a device via a 3GPP access technology, such as a base station, it is determined that a NAS COUNT corresponding to the 3GPP access technology can be used. In other words, the AMF node can check, using the uplink NAS COUNT that conforms to the 3GPP access technology and which is stored by the AMF node, the uplink NAS COUNT transmitted in the N2 message. If the N2 message arrives from a device via a non-3GPP access technology, such as an N3IWF node, it is determined that a NAS COUNT corresponding to the non-3GPP access technology can be used. In other words, the AMF node can check, using an uplink NAS COUNT that conforms to non-3GPP access technology and that is stored by the AMF node, the uplink NAS COUNT transmitted in the N2 message.

Method 2: The terminal may explicitly notify the AMF node of the source of the N2 message. For example, the N2 message may contain a bit that is used to indicate the access technology. For example, 0 represents 3GPP access technology and 1 represents non-3GPP access technology. Alternatively, the N2 message may contain a character string, for example, "NR" represents a 3GPP access technology and "wifi" represents a non-3GPP access technology.

Method 3: The AMF node determines, based on the access type information in the N2 message, the access technology used to transmit the N2 message. For example, the access type information is RAT type information (access type). If the N2 message comes from a device using 3GPP access technology, such as a base station, the access type indication in the N2 message is 3GPP access, so it is determined that a NAS COUNT corresponding to 3GPP access technology can be used. In other words, the AMF node can check, using the uplink NAS COUNT that conforms to the 3GPP access technology and which is stored by the AMF node, the uplink NAS COUNT transmitted in the N2 message.

Compared with the prior art in which the AMF node does not distinguish between the access technologies used by the received messages, in the above two methods, in this embodiment of the present invention, the AMF node can determine the access technology used by the received message, select the NAS COUNT corresponding to the access technology used received message.

Alternatively, in another implementation provided in this embodiment of the present invention, with reference to the method procedure corresponding to FIG. 11A and FIG. 11B, if the AMF node determines the second uplink NAS COUNT and the first downlink NAS COUNT that conform to the non-3GPP access technology in step 1111, the AMF node may further update the NAS key. This embodiment of the present invention provides four methods for updating a NAS key.

Method 1: generate a new Kamf (nKamf) using the previously used Kamf (oKamf), and after the AMF node generates nKamf, generate a new NAS key based on nKamf.

Here Kamf is the node's AMF root key.

Here nKamf = KDF(oKamf, novelty parameter). The novelty parameter may be an uplink NAS COUNT, a previously received AMF node, a COUNT, a parameter sent by the terminal to the AMF node, or a parameter that is negotiated between the terminal and the AMF node.

Method 2: generate nKamf using Kseaf and after the AMF node generates nKamf, generate a new nKamf based NAS key.

Here Kseaf is the node's AMF root key.

Here nKamf = KDF (Kamf, novelty parameter). The novelty parameter may be an uplink NAS COUNT previously received by the AMF node, or may be a counter value. For example, the initial value of the counter value is 0, and each time an AMF node generates a NAS key, the counter value is incremented by 1 to indicate that the AMF node generates a new key.

Method 3: The AMF node can generate a new NAS key based on the old Kamf (oKamf) and algorithm.

Here nKamf = KDF (oKamf, algorithm ID, selected algorithm and other parameter) and algorithm ID is the ID of the algorithm selected by the AMF node. The selected algorithm is the algorithm used by the end device and the AMF node to secure the NAS message.

The other parameter is a parameter used to specify the access technology. In particular, the other parameter may be in the form of a bit or in the form of an identifier. For example, it may be indicated that the other parameter corresponding to the 3GPP access technology is 0x01, the other parameter corresponding to the non-3GPP access technology is 0x10, and the other parameter corresponding to the fixed network access technology is 0x11.

The other parameter may alternatively be the value of a counter. For example, the initial value of the counter value is 0, and each time an AMF node generates a NAS key, the counter value is incremented by 1 to indicate that the AMF node generates a new key.

Method 4: generate a new NAS key based on the previously used NAS key.

New NAS key = (previously used NAS key, counter value). For example, the initial value of the counter value is 0, and each time an AMF node generates a NAS key, the counter value is incremented by 1 to indicate that the AMF node generates a new key.

It should be noted that if the AMF node generates a new NAS key, the AMF node may issue instructions using the NAS SMC message in the embodiment corresponding to FIG. 11A and FIG. 11B, a terminal for explicitly updating a key. Upon receiving the key renewal instruction, the terminal may update the key using one of the above four methods. The key update method of the end device is similar to the NAS key update method of the AMF node, and the NAS key update method is pre-configured in both the AMF node and the end device.

Alternatively, when the AMF node and end device change the access technology used, the NAS key may be updated. Alternatively, the NAS key may be updated when the case of using multiple access technologies switches to the case of using only one access technology, or when the number of simultaneously used access technologies decreases.

According to this method, the key is updated. Even if the attacker obtains the NAS key used when the AMF node communicates with the end device using multiple access technologies, the attacker cannot obtain the plaintext used when the end device subsequently communicates with the AMF node using a single access technology, thereby increasing safety.

It should be noted that in the embodiments of the present invention, an example is used for description in which the first access technology is a non-3GPP access technology and the second access technology is a 3GPP access technology. Alternatively, in a real application, the first access technology may be a 3GPP access technology and the second access technology may be a non-3GPP access technology. The method provided in the previous embodiments may be used when the first access technology and the second access technology, respectively, are two different access technologies supported by the terminal, or the method provided in the above embodiments may be used when the terminal accesses main network device using a variety of access technologies.

For example, if the first access technology is a fixed network access technology and the second access technology is a non-3GPP access technology, the implementation method is similar to that described in the previous embodiments. The embodiment corresponding to FIG. 11A and FIG. 11B may apply to a scenario in which a terminal has accessed an AMF node using 3GPP access technology and then accesses the same AMF node using fixed network access technology. The procedure in FIG. 11A and FIG. 11B may be replaced by a registration process in which the terminal device accesses the AMF node using fixed network access technology. The security method for the registration process is similar to the security method described in the embodiment of FIG. 11A and FIG. 11B and in which the terminal device accesses the AMF node using a non-3GPP access technology.

The foregoing mainly describes the solutions provided in the embodiments of the present invention in terms of interaction between different network elements. It should be understood that in order to implement the above functions, the terminal device and the host network device include respective hardware structures and/or software modules to perform the functions. With reference to the examples described in the embodiments disclosed in the present invention, the blocks and steps of the algorithm may be implemented by hardware or a combination of hardware and computer software in the embodiments of the present invention. Whether the function is implemented in hardware or in a hardware control method with computer software depends on the particular application and design constraint conditions of the technical solutions. For each specific application, a person skilled in the art can use different methods to implement the described functions, but it should be understood that the implementation is not beyond the technical solutions of the embodiments of the present invention.

In embodiments of the present invention, separation of functional blocks may be performed at the terminal device and the main network device based on the above method examples. For example, each function block may be obtained by dividing based on a corresponding function, or two or more functions may be integrated into one processing unit. An integrated block may be implemented in the form of hardware or may be implemented in the form of a software function block. It should be noted that the division into blocks in the embodiments of the present invention is an example and is simply a logical division of functions and may be another division in the actual implementation.

When an integrated block is used, FIG. 12 shows a schematic block diagram of an apparatus 1200 according to an embodiment of the present invention. Device 1200 may be implemented in software, or may be a terminal device, or may be a chip in a terminal device. The device 1200 includes a processing unit 1202 and a communication unit 1203. Processing unit 1202 is configured to control and monitor the operation of device 1200. For example, processing unit 1202 is configured to support device 1200 while performing step 501 and step 502 in FIG. 5, step 1001 in FIG. 10, step 1101, step 1105, step 1113, step 1117, and step 1118 in FIG. 11A and FIG. 11B, and/or another process of the technology described in this description. The communication unit 1203 is configured to communicate between the device 1200 and another network element (such as a core network device and an N3IWF node). For example, the communication unit 1203 is configured to support the device 1200 while performing step 1002, step 1003, and step 1007 in FIG. 10 and step 1102, step 1103, step 1104, step 1106, step 1112, step 1114, step 1116, and step 1119 in FIG. 11A and FIG. 11B. Device 1200 may further include a storage unit 1201 configured to store program code and data of device 1200.

Processor 1202 may be a processor or controller, such as a Central Processing Unit (CPU), a general purpose processor, a Digital Signal Processor (DSP), a user-programmable Application-Specified Integrated Circuit (ASIC). gate array (Field Programmable Gate Array, FPGA) or other programmable logic device, transistorized logic device, hardware component, or any combination thereof. Processing unit 1202 may implement or execute various examples of logical blocks, modules, and circuits described with reference to the content disclosed in the present invention. Alternatively, the processor may be a combination for implementing a computing function, such as a combination of one or more microprocessors, or a combination of a DSP and a microprocessor. The communication unit 1203 may be a transceiver, a transceiver circuit, a communication interface, or the like. The storage unit 1201 may be a memory.

When the processing unit 1202 is a processor, the communication unit 1203 is a transceiver, and the storage unit 1201 is a memory, the device 1200 in this embodiment of the present invention may be the terminal device shown in FIG. 13.

In FIG. 13 shows a simplified diagram of a possible implementation structure of a corresponding terminal device 1300 according to an embodiment of the present invention. Terminal 1300 includes a transmitter 1301, a receiver 1302, and a processor 1303. Processor 1303 may alternatively be a controller and is referred to as "controller/processor 1303" in FIG. 13. Alternatively, tag 1300 may further include a modem processor 1305, and modem processor 1305 may include an encoder 1306, a modulator 1307, a decoder 1308, and a demodulator 1309.

In one example, transmitter 1301 adjusts (eg, through analog conversion, filtering, amplification, and upconversion) the output sample and generates an uplink signal. The uplink signal is transmitted to the base station in the previous embodiments using an antenna. On the downlink, the antenna receives the downlink signal transmitted by the base station in the above embodiment. Receiver 1302 adjusts (eg, through filtering, amplifying, downconverting, and digitizing) the signal received from the antenna and provides an input sample. In modem processor 1305, encoder 1306 receives the overhead and signaling message to be sent on the uplink and processes (eg, through formatting, encoding, and interleaving) the overhead and signaling message. Modulator 1307 further processes (eg, through symbol mapping and modulation) the encoded overhead and the encoded signaling message and provides an output sample. A demodulator 1309 processes (eg, through demodulation) the input sample and provides a symbol estimate. Decoder 1308 processes (eg, by deinterleaving and decoding) the symbol estimate and provides decoded data and a decoded signaling message to be sent to terminal device 1300. Encoder 1306, modulator 1307, demodulator 1309, and decoder 1308 may be implemented by an integrated modem processor 1305 The units perform processing based on the radio access technology (eg, LTE access technologies and other advanced system) used in the radio access network. It should be noted that when tag 1300 does not include modem processor 1305, the aforementioned functions of modem processor 1305 may alternatively be implemented by processor 1303.

The processor 1303 monitors and controls the operation of the tag 1300 and is configured to perform processing performed by the tag 1300 in the above embodiments of the present invention. For example, processor 1303 is further configured to perform processing associated with the terminal in the manner shown in FIG. 5, fig. 10 and FIG. 11A and FIG. 11B and/or other process of technical solutions described in the present invention.

Moreover, tag 1300 may further include memory 1304, and memory 1304 is configured to store program code and data used for tag 1300.

When an integrated block is used, FIG. 14 shows a block diagram of another device 1400 according to an embodiment of the present invention. The device may be in the form of software, or may be a core network device, or may be a chip in a core network device. The device 1400 includes a processing unit 1402 and a communication unit 1403. Processing unit 1402 is configured to control and monitor the operation of device 1400. For example, processing unit 1402 is configured to support device 1400 while performing step 901 and step 902 in FIG. 9, steps 1004 - steps 1006 in FIG. 10, steps 1109 - steps 1111 in FIG. 11A and FIG. 11B and/or another process of the technology described herein. The communication unit 1403 is configured to communicate between the device 1400 and another network element (such as a terminal device or an N3IWF node). For example, the communication unit 1403 is configured to support the device 1400 in step 1001, step 1002, and step 1007 in FIG. 10 and step 1108, step 1112, step 1114 and step 1115 in FIG. 11A and FIG. 11B. Device 1400 may further include a storage unit 1401 configured to store program code and data of device 1400.

Processing unit 1402 may be a processor or controller, such as a CPU, general purpose processor, DSP, ASIC, FPGA, or other programmable logic device, transistorized logic device, hardware component, or any combination thereof. Processing unit 1402 may implement or execute various exemplary logical blocks, modules, and circuits described with reference to the content disclosed herein. Alternatively, the processor may be a combination for implementing a computing function, such as a combination of one or more microprocessors, or a combination of a DSP and a microprocessor. The communication block 1403 may be a communication interface. The communication interface has a common name. In a particular implementation, a communication interface may include a plurality of interfaces. For example, the communication interface may include an interface between the underlying network device and the terminal device and an interface between the underlying network device and the N3IWF node and/or other interface. The storage unit 1401 may be a memory.

When the processing unit 1402 is a processor, the communication unit 1403 is a communication interface, and the storage unit 1401 is a memory, the device structure 1400 in this embodiment of the present invention may be that of the network device shown in FIG. fifteen.

Fig. 15 shows a possible block diagram of a basic network device according to an embodiment of the present invention.

As shown in FIG. 15, the main network device 1500 includes a processor 1502, a communication interface 1503, and a memory 1501. Alternatively, the main network device 1500 may further include a bus 1504. The communication interface 1503, the processor 1502, and the memory 1501 may be connected to each other. using bus 1504. Bus 1504 may be a PCI bus, an EISA bus, or the like. Bus 1504 can be classified into an address bus, a data bus, a control bus, and the like. For ease of indicating the tire, only one bold line is indicated in FIG. 15. However, this does not mean that only one tire or only one type of tire is used.

The methods or steps of an algorithm described with reference to the content disclosed herein may be implemented in hardware or may be implemented in a software instruction by a processor. The software instruction may include a corresponding software module. The software module can be stored in RAM (Random Access Memory), Flash Memory, Read-Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable Read-Only Memory (Electrically EPROM, EEPROM), register, hard disk, removable hard disk, compact disc read only memory (CD-ROM), or storage medium in any other form well known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may be a component of the processor. The processor and storage medium may be located in an ASIC. Additionally, the ASIC may be located in the core network interface device. Of course, the processor and the storage medium may be installed in the core network interface device as discrete components.

In several embodiments presented in the present invention, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiment described is merely an example. For example, the division into blocks is simply a logical division of functions and may be another division in the actual implementation. For example, many blocks or components may be combined or integrated into another system, or certain functions may be ignored or not performed. Additionally, interconnections or direct connections or connections that are displayed or discussed can be implemented through some interfaces. Indirect connections or communication connections between devices or units may be implemented in electronic or other form.

Blocks described as separate parts may or may not be physically separate. Parts displayed as blocks may or may not be physical blocks, in other words, may be located in one position or may be distributed across multiple network devices. Some or all of the blocks may be selected according to actual needs in order to achieve the goals of the solutions of the embodiments.

Additionally, the functional blocks in the embodiments of the present invention may be integrated into a single processing block, or each of the functional blocks may be one, or two or more blocks may be integrated into one block. The integrated block may be implemented in hardware, or may be implemented in hardware in addition to the software functional block.

Based on the above descriptions of the implementations, one skilled in the art can clearly understand that the present invention can be implemented in software in addition to the required generic hardware or, of course, in hardware alone. In most cases, the former is the preferred implementation. Based on such an understanding, the technical solutions of the present invention, in essence, or part contributing to the prior art, can be implemented in the form of a software product. The computer program product is stored on a readable storage medium, such as a floppy disk, hard drive, or optical disk of a computer, and includes several instructions for instructing a computing device (which may be a personal computer, server, or network device) to perform the methods described in embodiments. implementation of the present invention.

The above descriptions are merely specific embodiments of the present invention, but are not intended to limit the protection scope of the present invention. Any modification or substitution disclosed herein shall fall within the scope of the present invention. Therefore, the scope of protection of this invention should be the subject of the protection of the claims.

Claims (51)

1. A non-access layer (NAS) message security method comprising the steps of: determining, by the device, a value of a first parameter, wherein the value of the first parameter is indicative of the access technology used to transmit the NAS message; wherein the first parameter is an input parameter used when the transmission security of the NAS message is performed; and performing, by the device, securing the NAS message based on the first parameter, the NAS key and the NAS COUNT corresponding to the access technology used to transmit the NAS message, wherein the specified device is a terminal device, a chip in a terminal device, or a primary network device. 2. The method of claim 1, further comprising the step of: determining, by the device, the access technology used to transmit the message to the NAS prior to determining the value of the first parameter. 3. The method according to claim 1 or 2, wherein the input parameter is BEARER. 4. The method according to any one of paragraphs. 1-3, wherein the access technology used to transmit the NAS message contains a 3rd Generation Partnership Project (3GPP) access technology or a non-3GPP access technology. 5. The method of claim 4, wherein when the access technology used to transmit the NAS message is a 3GPP access technology, the value of the first parameter is set to the first value. 6. The method of claim 4, wherein when the access technology used to transmit the NAS message is a non-3GPP access technology, the value of the first parameter is set to the second value. 7. The method according to any one of paragraphs. 1-6, wherein the NAS message is a NAS message to be transmitted, wherein the step of executing, by a device, securing the NAS message comprises at least one of: encrypting the NAS message; or performing integrity protection of the NAS message. 8. The method of claim 7, further comprising the step of: transmitting, by the device, a NAS protected message, wherein the NAS protected message includes some NAS COUNT bits. 9. The method according to any one of paragraphs. 1-6, wherein the NAS message is a received NAS message, wherein the step of performing security for the NAS message comprises a sub-step of: decrypting the NAS message; or performing integrity protection verification of the received NAS message. 10. The method according to any one of paragraphs. 1-9, wherein when the device is a terminal device or a chip in a terminal device, the device supports at least two access technologies and separately supports corresponding NAS COUNTs for each of the at least two access technologies. 11. The method according to any one of paragraphs. 1-9, in which, when the device is the main network device, the device separately supports the corresponding NAS COUNT for each of the at least two access technologies. 12. The method of claim 11, wherein the underlying network device is an access and mobility management function (AMF) node. 13. A non-access layer (NAS) message security device, comprising: a processing unit, configured to: determine the value of the first parameter, wherein the value of the first parameter represents the access technology used to transmit the NAS message; wherein the first parameter is an input parameter used when the transmission security of the NAS message is performed; and performing security for the NAS message based on the first parameter, the NAS key and the NAS COUNT corresponding to the access technology used to transmit the NAS message, wherein the specified device is a terminal device, a chip in a terminal device, or a primary network device. 14. The apparatus of claim 13, wherein the processing unit is further configured to: determining the access technology used to send the message to the NAS before determining the value of the first parameter. 15. The apparatus of claim 13 or 14, wherein the input parameter is BEARER. 16. The device according to any one of paragraphs. 13-15, wherein the access technology used to transmit the NAS message comprises a 3rd Generation Partnership Project (3GPP) access technology or a non-3GPP access technology. 17. The apparatus of claim 16, wherein when the access technology used to transmit the NAS message is a 3GPP access technology, the value of the first parameter is set to the first value. 18. The apparatus of claim 16, wherein when the access technology used to transmit the NAS message is a non-3GPP access technology, the value of the first parameter is set to the second value. 19. The device according to any one of paragraphs. 13-18, wherein the NAS message is a NAS message to be transmitted, wherein the processing unit is configured to perform security on the NAS message by doing at least one of: encrypting the NAS message to be transmitted; or performing NAS integrity protection of the message to be transmitted. 20. The device according to claim 19, in which the device further comprises a communication unit; wherein the communication unit is configured to transmit the NAS secure message, wherein the NAS secure message includes some NAS COUNT bits. 21. The device according to any one of paragraphs. 13-19, wherein the NAS message is a received NAS message, wherein the processing unit is configured to perform security on the NAS message by doing at least one of: decrypting the received NAS message; or performing integrity protection verification of the received NAS message. 22. The device according to any one of paragraphs. 13-21, wherein when the device is a tag or a chip in the tag, the tag is configured to support at least two access technologies and separately support corresponding NAS COUNTs for each of the at least two access technologies. 23. The device according to any one of paragraphs. 13-21, characterized in that when the device is a primary network device, it is configured to separately support the corresponding NAS count for each of the at least two access technologies. 24. The device of claim 23, wherein the device is an access and mobility management function (AMF) node. 25. A computer-readable storage medium that stores instructions that cause, when executed by a computer, the computer to execute the method according to any one of paragraphs. 1-12. 26. A non-access layer (NAS) message security device, comprising: at least one processor; and a memory coupled to the at least one processor and storing program instructions causing, when executed by the at least one processor, the device to execute the method of any one of claims. 1-12. 27. Communication system containing the terminal device and the main network device; wherein terminal device is configured to: determining a value of a first parameter, wherein the value of the first parameter represents the access technology used to transmit the Non-Access Layer (NAS) message; wherein the first parameter is an input parameter used when the transmission security of the NAS message is performed; and performing security for the NAS message based on the first parameter, the NAS key and the NAS COUNT corresponding to the access technology used to transmit the NAS message; transmitting a secure NAS message to the underlying network device; a the main network device is configured to: receiving a secure NAS message from the end device; determining the value of the first parameter; performing security for the NAS protected message based on the first parameter, the NAS key and the NAS COUNT corresponding to the access technology used to transmit the NAS protected message.

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