WO2014180390A2

WO2014180390A2 - Trunking group communication public security implementation method and device

Info

Publication number: WO2014180390A2
Application number: PCT/CN2014/078185
Authority: WO
Inventors: 潘磊
Original assignee: 中兴通讯股份有限公司
Priority date: 2013-12-20
Filing date: 2014-05-22
Publication date: 2014-11-13
Also published as: CN104735626A; WO2014180390A3

Abstract

The present invention provides a trunking group communication public security implementation method and device, wherein said method comprises: when a terminal within a group initiates a group call, receiving a random number from a network side; in accordance with said random number and with a root key obtained in advance from the network side, generating an intermediate parameter, and also a first key used for non-access stratum (NAS) decryption and integrity protection; generating a second key in accordance with said intermediate parameter; in accordance with the second key, engaging in the decryption and integrity protection of data coming from a trunking group control channel (TGCCH) and from a trunking group traffic channel (TGTCH). The above technical solution provided in the present invention solves the problem of the related art whereby a terminal is not supported on a downlink shared channel in regard to a point-to-multipoint type of trunking group traffic, thus achieving multi-user security. A security mechanism for trunking group UE terminal trunking group communication public channels is thus implemented.

Description

The present invention relates to the field of communications, and more particularly to a method and apparatus for implementing public security of trunking communications. BACKGROUND In an existing LTE system, a downlink public broadcast channel is not secured, and a dedicated channel has its own unique security parameters. However, due to the special needs of the cluster, multiple users in the same group need to listen to a common channel together, so multiple security parameters are required to be synchronized. At present, the related technologies do not support the problem that the terminal is on the downlink common channel and implements the multi-user security for the point-to-multiple cluster service. Currently, no effective solution has been proposed. SUMMARY OF THE INVENTION The present invention provides a method and an apparatus for public communication of a cluster communication, so as to at least solve the problem in the related art that the terminal does not support the multi-user security for the point-to-multiple cluster service on the downlink common channel. In order to achieve the above object, according to an aspect of the present invention, a method for implementing public security of a trunking communication is provided, including: when a terminal in a group initiates a group call, receiving a random number from a network side; And a root key generated in advance from the network side to generate an intermediate parameter, and a first key for non-access stratum (Non-Access Stratum, NAS) decryption and integrity protection; generating a second according to the intermediate parameter Keys: Decrypt and integrity protect data from a trunk control group control channel (TCCCH) and a trunking group traffic channel (TGTCH) according to the second key. Preferably, generating the second key according to the intermediate parameter comprises: generating the second key according to the intermediate parameter by using a Key Distribution Algorithm (KDF) algorithm. Preferably, receiving the random number from the network side, comprising: receiving a paging message on the network side; and acquiring the random number from the paging message. Preferably, the first key includes: a first subkey for NAS decryption, a second subkey for NAS integrity protection; and/or the second key, including: A third subkey of signaling decryption and integrity protection of TGCCH, a fourth subkey for data decryption of TGTCH. Preferably, the method further includes: after the group call ends, retaining the root key, and deleting the random number, the first key, and the second key. Preferably, the method further includes: in decrypting the data, decrypting data received by the terminal in the group by using the same Count value. Preferably, the method further includes: receiving, before the terminal initiates the group call, the root key sent by the network side. In order to achieve the above object, according to still another aspect of the present invention, a device for implementing public security of a trunking communication is provided, including: a receiving module, configured to receive a random time from a network side when a terminal in a group initiates a group call a first generation module, configured to generate an intermediate parameter according to the random number and a root key acquired in advance from the network side, and a first key set to non-access stratum NAS decryption and integrity protection; second generation a module, configured to generate a second key according to the intermediate parameter; and a processing module configured to decrypt and integrity protect data from the cluster control channel TGCCH and the cluster traffic channel TGTCH according to the second key. Preferably, the second generating module is further configured to generate the second key by using a KDF algorithm according to the intermediate parameter. Preferably, the receiving module includes: a receiving unit, configured to receive a paging message on the network side; and an acquiring unit, configured to acquire the random number from the paging message. According to the present invention, when a terminal in a group initiates a group call, according to a random number received from the network side and a root key acquired from the network side in advance, a non-access layer NAS decryption and integrity protection is generated. The first key and the technical solution for generating the intermediate parameter of the second key for decrypting and integrity protection of the data from the cluster control channel TGCCH and the trunk traffic channel TGTCH channel solve the related art, and do not support the terminal in the downlink On the common channel, the problem of multi-user security is achieved for point-to-multiple cluster services. Therefore, the security mechanism of the downlink common channel of the user equipment (User Equipment, UE for short) is implemented. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1 is a flowchart of a method for implementing public communication of trunking communication according to an embodiment of the present invention; FIG. 2 is a schematic flowchart of generating Kgnasenc according to a root key Kg according to an embodiment of the present invention; 3 is a schematic flowchart of generating Kgnasint according to a root key Kg according to an embodiment of the present invention; FIG. 4 is a schematic flowchart of generating Kgenb according to a root key Kg according to an embodiment of the present invention; FIG. FIG. 6 is a flow chart of generating Kgrrcenc according to Kgenb according to an embodiment of the present invention; FIG. 7 is a schematic flowchart of generating Kgrrcint according to Kgenb according to an embodiment of the present invention; FIG. 8 is a schematic diagram of generating Kgrrcint according to Kgenb according to an embodiment of the present invention; FIG. 9 is a structural diagram of a cluster system according to a preferred embodiment of the present invention; FIG. 10 is a structural diagram of a cluster communication public security implementation apparatus according to an embodiment of the present invention; A further block diagram of the cluster communication public security implementation apparatus of the embodiment. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. FIG. 1 is a flowchart of a method for implementing cluster communication public security according to an embodiment of the present invention. As shown in FIG. 1, the method includes: Steps S102 to S108. S102: When a terminal in the group initiates a group call, receiving a random number from the network side; before the terminal in the group initiates the group call, the method may further include the following steps: the terminal starts the registration, and the network side initiates the group information update and receives. The root key sent by the network side. The root key provided by the embodiment of the present invention is different from the existing LTE system. For example, in the existing LTE system, the root key Kg is solidified in the SIM card. However, the root key provided by the embodiment of the present invention has the same root key Kg for the users of the same group, and therefore cannot be solidified in the SIM card. Instead, it is carried to each terminal through NAS signaling. The NAS signaling is LTE security protected, so it is secure. In the step S102, receiving the random number from the network side may include: receiving the paging message on the network side; and acquiring the random number from the paging message.

S104: Generate an intermediate parameter according to the random number and a root key acquired in advance from the network side, and a first key used for NAS decryption and integrity protection. In this embodiment, the first key may include: a first subkey for NAS decryption, and a second subkey for NAS integrity protection. In this embodiment, the first subkey and the second subkey in the first key determined according to the random number and the root key may be specifically: K value Kgnasenc used for NAS layer encryption and decryption and The K value Kgnasint for the integrity protection of the NAS layer; the above intermediate parameter may be specifically: a K value Kgenb for further generating an air interface key. As shown in FIG. 2, FIG. 2 is a schematic flowchart of generating Kgnasenc according to a root key Kg according to an embodiment of the present invention. In Figure 2, the input parameters used are the NAS encryption algorithm Alg, the group id, and the random number Rand, where the parameters used are as follows: (1) The KDF function input key is Kg; (2) Constructing a byte string The parameters of s are: FC=0xl5 Parameter pO=Alg-ID, encryption algorithm identification, 0x00 when using EEA0 algorithm, 0x01 when using 128-EEA1 algorithm, 0x02 when using 128-EEA2 algorithm; parameter L0 = 0x00 0x01; Parameter pi = NAS-enc-alg, 0x01; parameter L1 = 0x00 0x01; p2 = GID, group identification, 64bit; L2 = 0x00 0x08; p3 = Rand; L3 = 0x00 0x04 (3) KDF function outputs 256bit dense Key, since the NAS encryption algorithm needs to use a 128-bit input key, the 256-bit low 128-bit that intercepts the KDF output is Kgnasenc. As shown in FIG. 3, FIG. 3 is a schematic flowchart of generating Kgnasint according to the root key Kg according to an embodiment of the present invention. In Figure 3, the input parameters used are the NAS integrity protection algorithm Alg, the group ID, and the random number Rand, where the parameters used are as follows: (1) The KDF function input key is Kg; (2) Construct word The parameters of the section string s are: FC = 0x15; parameter p0 = Alg-ID, encryption algorithm identifier, 0x00 when using EIA0 algorithm, 0x01 when using 128-EIA1 algorithm, 0x02 when using 128-EIA2 algorithm; L0 = 0x00 0x01; Parameter pi = NAS-int-alg, 0x02; Parameter LI = 0x00 0x01; p2 = GID, group identification, 64bit; L2 = 0x00, 0x08; p3 = Rand; L3 = 0x00 0x04 (3) KDF function The 256-bit key is output. Since the NAS integrity protection algorithm needs to use a 128-bit key, the 256-bit low 128-bit of the KDF output is Kgnasint. As shown in FIG. 4, FIG. 4 is a root key Kg according to an embodiment of the present invention. A schematic diagram of the process of generating Kgenb. In Figure 4, where the input parameter is SN and the random number Rand, the parameters used are as follows: (1) The input key of the KDF function is Kg; (2) The parameters of constructing the byte string s are: FC = 0xl l The parameter pO = SN id, SN id is shown by the mobile country code (Mobile Country Code, MCC for short) and the mobile network code (Mobile Network Code, MNC for short) as shown in the following Table 1 (specifically, the LTE standard can be queried). Rule composition: Table 1

MCC digi t 2― ___ I CC tfiflit ί

MNC digit 3 MCC Jiiii : 3

C diflit 2 I MNC turns it 1 where the length of the parameter LO = ρθ is 0x00 0x03 parameter pi = Rand, 32bit, Rand is the length of a random number parameter LI = pi generated by PHR each time the group call is established, 0x00 0x04. Among them, the numbers 1-8 represent 8 bits in the byte.

S106: Generate a second key according to the foregoing intermediate parameter. The second key is generated according to the intermediate parameter, and the second key includes: a third subkey used for signaling decryption and integrity protection of the TGCCH, and a data decryption for TGTCH. Four subkeys. In this embodiment, the third subkey may be specifically: Kgrrcint, Kgrrcenc, and the fourth subkey may be specifically: Kgupenc. As shown in FIG. 5, FIG. 5 is a schematic flowchart of generating Kgupenc according to Kgenb according to an embodiment of the present invention. In Figure 5, the input parameters used are the UP encryption algorithm Alg, the group id, and the random number Rand, where the parameters used are as follows: (1) The KDF function input key is Kgenb; (2) Constructing a byte string The parameters of s are: FC = 0x15 parameter p0 = Alg-ID, encryption algorithm identification, 0x00 when using EEA0 algorithm, 0x01 when using 128-EEA1 algorithm, 0x02 when using 128-EEA2 algorithm; parameter L0 = 0x00 0x01; Parameter pi = UP-enc-alg, 0x05; Parameter LI = 0x00 0x01; p2 = GID, group identification, 64bit; L2 = 0x00, 0x08; p3 = Rand; L3 = 0x00 0x04 (3) KDF function output 256bit Key, since the UP encryption algorithm needs to use a 128-bit key, the 256-bit low 128-bit that intercepts the KDF output is Kgupenc. As shown in FIG. 6, FIG. 6 is a schematic flowchart of generating Kgrrcenc according to Kgenb according to an embodiment of the present invention. In Figure 6, the input parameters used are the RRC encryption algorithm Alg, the group id, and the random number Rand, where the parameters used are as follows: (1) The KDF function input key is Kgenb; (2) Constructing a byte string The parameters of s are: FC = 0x15 Parameter p0 = Alg-ID, encryption algorithm identification, 0x00 when using EEA0 algorithm, 0x01 when using 128-EEA1 algorithm, 0x02 when using 128-EEA2 algorithm; parameter L0 = 0x00 0x01; Parameter pi = RRC-enc-alg, 0x03; Parameter LI = 0x00 0x01; p2 = GID, group identification, 64bit; L2 = 0x00, 0x08; p3 = Rand,; L3 = 0x00 0x04 (3) KDF function output 256bit The key, because the UP encryption algorithm needs to use a 128-bit key, so the 256-bit low 128-bit of the KDF output is Kgrrcenc. As shown in FIG. 7, FIG. 7 is a schematic flowchart of generating Kgrrcint according to Kgenb according to an embodiment of the present invention. In Figure 7, the input parameters used are the RRC integrity protection algorithm Alg, the group id, and the random number Rand, where the parameters used are as follows: (1) The KDF function input key is Kgenb; (2) Construct word The parameters of the section string s are: FC = 0xl5 parameter pO = Alg-ID, encryption algorithm identifier, 0x00 when using EEA0 algorithm, 0x01 when using 128-EEA1 algorithm, 0x02 when using 128-EEA2 algorithm; parameter L0 = 0x00 0x01; Parameter pi = RRC-int-alg, 0x04; Parameter LI = 0x00 0x01; p2 = GID, group identification, 64bit; L2 = 0x00, 0x08; p3 = Rand; L3 = 0x00 0x04 (3) KDF function output The 256-bit key, because the UP encryption algorithm needs to use a 128-bit key, so the 256-bit low 128-bit of the KDF output is Kgrrcint.

S108: Decrypt and integrity protect data from the TGCCH and the TGTCH according to the second key. After the execution of the above steps S102 to S108 is completed, the signaling and data of the TGCCH and TGTCH channels are started to be received, and normal cluster services are performed. The signaling of the TGCCH channel is decrypted and integrity protected by the public security keys Kgrrcenc, Kgrrcint, and the user plane data of the TGTCH is decrypted by the key Kgupenc, and after the group call ends, the root key is retained, and the above is deleted. a random number, the first key described above, and the second key. The decryption process involved in this embodiment: that is, in the process of decrypting the above data, the data received by the terminal in the group is decrypted by using the same count Count value. In the existing LTE system, the user decryption needs to use a count value, count=hfn+sn, and hfn is incremented by 1 each time the sn is flipped. In the embodiment of the present application, in order to enable users who access at different times to successfully decrypt, the design is to cure hfn, and when the sn is flipped, the hfn is not incremented. Therefore, the user who accesses first and later access can correctly decrypt the user plane data. In order to better understand the above decryption process, FIG. 8 is a schematic diagram of decryption of steady state data according to an embodiment of the present invention. As shown in FIG. 8, based on the principle shown in FIG. 8, the following processing steps can be used to decrypt the steady state data. Step 1: Obtain the corresponding key value, BRARER value, data length length, encryption and decryption direction direction, and count value (where count value = hfn + sn, since the sn flip does not increment hfn, each terminal can receive e B by receiving The same count value is calculated for the data packet). Step 2: Obtain a key stream block by using an encryption algorithm. Step 3: Encrypt the data stream to be encrypted and the generated key stream block. Through the above steps, when the group call is initiated by the terminal in the group, the non-access layer NAS decryption and integrity protection are generated according to the random number received from the network side and the root key acquired from the network side in advance. The first key and the technical solution for generating the intermediate parameters of the second key for decrypting and integrity protection of the data from the cluster control channel TGCCH and the trunk traffic channel TGTCH channel are solved, and the related art does not support the terminal in On the downlink common channel, the problem of multi-user security is achieved for point-to-multiple cluster services. Thereby, the security mechanism of the downlink common channel of the cluster UE is realized. The random number provided by the embodiment of the present invention is carried in the paging, and the purpose is to enable each group call to generate a different key. In order to better understand the implementation process of the above-mentioned cluster communication public security, FIG. 9 is an architectural diagram of a cluster system according to a preferred embodiment of the present invention. As shown in FIG. 9, the following steps 1 to 3 are mainly included. Step 1: The core network sends the Kg corresponding to each group to the terminal through the group information update process. Step 2: A group initiates a group call, and the network side generates a random number, which is sent to the terminal of the group through paging.

(UE, User Equipment). Step 3: The terminal calculates corresponding key values for the integrity protection and decryption by using the random numbers GroupCallRand and Kg and the solidified security algorithm. The design of the random number GroupCallRand: Kg is unchanged for multiple group calls of the same group. In order not to be easily cracked, it is required to have different keys every time the group call is initiated, and the present invention is implemented. The random number provided by the example is carried in the paging, and the purpose is to enable each group call to generate a different key. It should be noted that, in FIG. 9, the PDS is an abbreviation of Personal Digital System, which can be translated into a personal digital system, PHS is an abbreviation of Personal Handy phone System, and can be translated into a handheld telephone system, and e B is an abbreviation of E-UTRAN NodeB. Can be translated into an evolved base station. In this embodiment, a device for implementing the public communication of the cluster communication is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments. The descriptions of the modules involved in the device are described below. . As used hereinafter, the term "module" may implement a combination of software and/or hardware of a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware, is also possible and conceivable. FIG. 10 is a structural diagram of an apparatus for implementing cluster communication public security according to an embodiment of the present invention. As shown in FIG. 10, the apparatus includes: a receiving module 102, a first generating module 104, a second generating module 106, and a processing module 108. The respective modules are described below. The receiving module 102 is configured to receive a random number from the network side when the terminal in the group initiates the group call. A further improvement of the foregoing technical solution in the embodiment of the present invention is that the receiving module 102 is further configured to generate the second key by using a KDF algorithm according to the intermediate parameter. The first generation module 104 is connected to the receiving module 102, and is configured to generate an intermediate parameter according to the random number and a root key acquired in advance from the network side, and a first key set as a non-access stratum NAS decryption and integrity protection. . The second generation module 106 is connected to the first generation module 104 and configured to generate a second key according to the intermediate parameter. The processing module 108 is coupled to the second generation module 106 and configured to decrypt and integrity protect data from the TGCCH and the TGTCH according to the second key. In this embodiment, as shown in FIG. 11, the receiving module 102 may further include: a receiving unit 1022, configured to receive a paging message on the network side; an obtaining unit 1024, connected to the receiving unit 1022, configured to be from the paging Obtain the above random number in the message. When the group call is initiated by the terminal in the group, the first generation module 104 generates a non-connection according to the random number received by the receiving module 102 from the network side and the root key acquired in advance from the network side. The first key of the inbound NAS decryption and integrity protection and the processing module 108 generate a second key according to the second generation module 106 to decrypt and secure the data from the cluster control channel TGCCH and the trunk traffic channel TGTCH channel. The technical solution of the parameter solves the problem in the related art that the terminal is not supported on the downlink common channel, and the multi-user security is realized for the point-to-multiple cluster service. Thereby, the security mechanism of the downlink common channel of the cluster UE is realized. The random number provided by the embodiment of the present invention is carried in the paging, and the purpose is to enable each group call to generate a different key. In summary, the foregoing technical solutions provided by the embodiments of the present invention achieve the following effects: The related art does not support the problem that the terminal does not support the cluster service on the downlink common channel and achieves multi-user security. . Thereby, the security mechanism of the downlink common channel of the cluster UE is realized. The random number provided by the embodiment of the present invention is carried in the paging, and the purpose is to enable each group call to generate a different key. Obviously, those skilled in the art should understand that the above-mentioned devices or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. Perform the steps shown or described, or separate them into individual integrated circuit modules, or Multiple of these modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention. Industrial Applicability In the embodiment of the present invention, when a terminal in a group initiates a group call, according to a random number received from the network side and a root key acquired in advance from the network side, the NAS decryption and the non-access layer are generated. The first key of the integrity protection and the technical solution for generating the intermediate parameters of the second key for decrypting and integrity protection of the data from the cluster control channel TGCCH and the trunk traffic channel TGTCH channel are solved in the related art, Supporting the terminal to achieve multi-user security for point-to-multiple cluster services on the downlink common channel. Thereby, the security mechanism of the downlink common channel of the cluster UE is realized. Therefore, it has industrial applicability.

Claims

Claim

1. A method for implementing public communication of cluster communication, comprising:

When a terminal in the group initiates a group call, receiving a random number from the network side;

Generating an intermediate parameter according to the random number and a root key acquired in advance from the network side, and a first key for non-access stratum NAS decryption and integrity protection;

Generating a second key according to the intermediate parameter;

The data from the cluster control channel TGCCH and the trunked traffic channel TGTCH is decrypted and integrity protected according to the second key.

2. The method according to claim 1, wherein generating the second key according to the intermediate parameter comprises: generating the second key by using a key segmentation algorithm KDF algorithm according to the intermediate parameter.

3. The method according to claim 1, wherein receiving a random number from the network side comprises:

Receiving a paging message on the network side;

Obtaining the random number from the paging message.

4. The method according to claim 1, wherein

The first key includes: a first subkey for NAS decryption, a second subkey for NAS integrity protection; and/or

The second key includes: a third sub-key for signaling decryption and integrity protection of TGCCH, and a fourth sub-key for data decryption of TGTCH.

5. The method according to claim 1, further comprising:

After the group call ends, the root key is retained, and the random number, the first key, and the second key are deleted.

The method according to any one of claims 1 to 5, wherein the method further comprises: using the same count for data received by terminals in the group during decryption of the data The Count value is decrypted.

The method according to any one of claims 1 to 5, further comprising: Before the terminal initiates the group call, receiving the root key sent by the network side. A device for implementing public communication of cluster communication, comprising:

The receiving module is configured to receive a random number from the network side when the terminal in the group initiates the group call, and the first generating module is configured to generate an intermediate parameter according to the random number and the root key acquired in advance from the network side, And a first key set to non-access stratum NAS decryption and integrity protection;

a second generating module, configured to generate a second key according to the intermediate parameter;

The processing module is configured to decrypt and integrity protect data from the cluster control channel TGCCH and the cluster traffic channel TGTCH according to the second key. The apparatus according to claim 8, wherein the second generation module is further configured to generate the second key using a KDF algorithm according to the intermediate parameter. The device according to claim 8, wherein the receiving module comprises:

a receiving unit, configured to receive a paging message on the network side;

And an obtaining unit, configured to obtain the random number from the paging message.