WO2011003352A1

WO2011003352A1 - Method and device for protecting terminal privacy

Info

Publication number: WO2011003352A1
Application number: PCT/CN2010/075041
Authority: WO
Inventors: 冯成燕; 滕志猛
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-07-08
Filing date: 2010-07-07
Publication date: 2011-01-13
Also published as: CN101610511A

Abstract

A method for protecting terminal privacy includes: when a terminal accesses a network initially or re-accesses the network, a base station receives a ranging request message from the terminal, wherein the ranging request message carries a safe calculation value of a Medium Access Control (MAC) address calculated by the terminal and the safe calculation value is used for protecting the real terminal MAC address and identifying the terminal; and the base station calculates an air interface key by using the safe calculation value after the terminal successfully completes authentication/authorization. A device for protecting terminal privacy is disclosed as well. The present invention solves the problem that the plaintext transmission of the MAC address will bring risks, and improves the security of a system.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a method and apparatus for protecting terminal privacy. BACKGROUND OF THE INVENTION The Institute of Electrical and Electronic Engineers (IEEE) 802.16 standard system is mainly for metropolitan area networks. Its main objective is to develop the physical layer of the air interface of the wireless access system operating in the 2 ~ 66 GHz band. (Physical, referred to as PHY) and Media Access Control (MAC) specifications, as well as conformance testing related to air interface protocols and coexistence specifications between different wireless access systems. According to whether it supports mobile characteristics, the IEEE 802.16 standard can be divided into fixed broadband wireless access air interface standard and mobile broadband wireless access air interface standard. Among them, 802.16d belongs to the fixed wireless access air interface standard, which was in 2004. It was approved by the IEEE 802 committee in June and released under the name IEEE 802.16-2004. 802.16e is a mobile broadband wireless access air interface standard. It was adopted by the IEEE 802 committee in November 2005 and is released under the name IEEE 802.16-2005. The Worldwide Interoperability for Microwave Access (WiMAX) is based on the IEEE 802.16 air interface specification and has become the most influential broadband wireless access technology in the world. Currently, the IEEE is developing the 802.16m standard. This standard is to study the next evolution path of WiMAX, the goal is to become the next generation mobile communication technology, and finally submit the technical proposal to the International Telecommunication Unit (ITU) to become the ITU's advanced international wireless communication system (International Mobile Telecommunication) Advance, referred to as IMT-Advanced, is one of the standards. This standard will be compatible with the existing 802.16e specification.

802.16m System Requirement Document (SRD) stipulates that the privacy of the terminal needs to be protected, that is, the terminal media access control address (AMS MAC Address) needs to be protected in the clear text transmission to avoid attackers. This address can be obtained to threaten the privacy of the terminal. To achieve this goal, the 16m System Description Document (SDD) defines two types of mobile station identifiers, namely, The mobile station identifier (Temporary Station ID, TSTID for short) and the official mobile station identifier (Station ID, referred to as STID), both identifiers are unique within the base station range. The TSTID is uniquely allocated by the base station for temporarily identifying the terminal in the process of the initial network access of the terminal. Specifically, the terminal reports its own AMS MAC Address to the base station in the RNG-REQ message. The base station sends the TSTID allocated for the terminal to the terminal in the Ranging Response (RNG-RSP) message, and the subsequent message interaction uses the TSTID to identify the terminal until the base station distributes the STID allocated for the terminal to the terminal during the registration process. The transmission of STID requires a protection mechanism. The base station then releases the TSTID and uses the STID to identify the terminal in a subsequent flow. However, this method only protects the mapping relationship between AMS MAC Address and STID, and still does not solve the risk of AMS MAC Address plaintext transmission. Since the attacker can intercept the address, it will forge or track the user's whereabouts. Summary of the invention

The present invention has been made in the prior art without solving the problem of the risk caused by the AMS MAC Address transmission. Therefore, the main object of the present invention is to provide a protection scheme for terminal privacy to solve the above problem. In order to achieve the above object, according to an aspect of the present invention, a method of protecting a terminal privacy is provided. The method for protecting the privacy of the terminal according to the present invention includes: when the terminal initially enters the network or re-enters the network, the base station receives the ranging request message from the terminal, where the ranging request message carries the media connection calculated by the terminal. Entering a security calculation value of the control address, the security calculation value is used to protect the real terminal media access control address and identify the terminal; after the terminal successfully completes the authentication and is authorized, the base station calculates the air interface key by using the above security calculation value. In order to achieve the above object, according to another aspect of the present invention, a protection device for terminal privacy is provided. The device for protecting the security of the terminal according to the present invention includes: a first receiving module, configured on the base station side, configured to receive a ranging request message from the terminal when the terminal initially enters the network or re-enters the network, where the ranging request message is carried The security calculation value of the media access control address calculated by the terminal, the security calculation value is used to protect the real terminal media access control address and identify the terminal; the first calculation module is set on the base station side, and is used to successfully complete the authentication at the terminal. / Authorization, the air interface key is calculated using the security calculation value received by the first receiving module. According to the present invention, the method for calculating the air interface key by using the security calculation value of the media access control address calculated by the terminal from the terminal is used by the base station, and the related art does not solve the problem caused by the AMS MAC Address plaintext transmission. The issue of risk, which in turn increases the security of the system. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flowchart of a method for protecting terminal privacy according to an embodiment of the present invention; FIG. 2 is an interaction of an implementation method for terminal privacy protection in a wireless communication system according to an embodiment of the present invention; 3 is a schematic diagram of generating an airborne derived key according to an embodiment of the present invention; FIG. 4 is an interaction flowchart according to Embodiment 4 of the present invention; FIG. 5 is an interaction flow according to Embodiment 5 of the present invention; Figure 6 is a block diagram showing the interaction of the terminal privacy protection apparatus according to the sixth embodiment of the present invention; Figure 7 is a block diagram showing the structure of the terminal privacy protection apparatus according to the embodiment of the present invention; A preferred block diagram of the protection device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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. The invention will be described in detail below with reference to the drawings in conjunction with the embodiments. Embodiment 1 This embodiment considers that the terminal privacy defined by 802.16m (AMS Privacy) does not solve the problem caused by the AMS MAC Address plaintext transmission, and provides a terminal privacy protection scheme, which is initially implemented in the terminal. When accessing the network or re-entering the network, the terminal calculates the security operation value of the terminal MAC address, and sends the terminal MAC address security operation value to the ranging request message. Base station. After the terminal successfully completes the authentication and is authorized, the terminal and the network side calculate the relevant air interface key by using the terminal MAC address security operation value when calculating the derived key of the air interface. 1 is a flowchart of a method for protecting privacy of a terminal according to an embodiment of the present invention. As shown in FIG. 1, the method includes the following steps: step S102 to step 4: S: Step S102, initial network access in the terminal Or the re-entry network, the base station receives the ranging request message from the terminal, where the ranging request message carries the security calculation value of the media access control address calculated by the terminal, and the security calculation value is used to protect the real terminal MAC address and Identify the terminal. Preferably, the security calculation value may include at least one of the following: a hash value, an encryption operation value, and the like. Preferably, before the terminal calculates the security calculation value of the media access control address, and sends a measurement request message to the base station, the base station sends a measurement response message to the terminal, and carries the security calculation value therein to indicate the measurement giant. The response message belongs to the terminal. For example, the input parameters for calculating the terminal MAC address security operation value are: a terminal MAC address, and/or a random number Random AMS generated by the terminal, and/or a random number Random ABS generated by the base station, and/or a base station identifier ABSID, that is, The terminal may calculate the security operation value according to at least one of the terminal MAC address and the other three parameters mentioned above. Step S104: After the terminal successfully completes the authentication/authorization, the base station calculates the air interface key using the security calculation value. Preferably, at the same time, the terminal calculates the air interface key using the security calculation value. For example, the air interface key may include at least one of the following: · an authorization key (Authorization Key, abbreviated as AK), a Cipher-based Message Authentication Code (CM AC) KEY, and a transmission encryption key. (Transmission Encrypt Key, TEK for short), Key Encrypt Key (KEK), hereinafter, preferably, the method may further include the following operations: after successfully completing the three-way handshake process, the terminal may In the registration request message REG-REQ, ^! takes its own AMS MAC Address and reports it to the base station. The transmission of the AMS AMC Address needs to be encrypted. The base station receives the registration request message from the terminal, where the registration request message carries the media of the terminal. The access control address, the registration request message is encrypted by the terminal-based air interface key; the base station assigns the mobile station identifier to the terminal, and encrypts the registration response message carrying the mobile station identifier according to the air interface key, and sends the encryption to the terminal. Post-registration response message. Embodiment 2 FIG. 2 is a wireless communication according to an embodiment of the present invention. Method for implementing terminal privacy protection in system As shown in FIG. 2, an implementation method for terminal privacy protection in a wireless communication system includes the following steps S201 to S211: Step S201, the terminal scans a downlink (downlink, DL for short) channel, and The base station establishes synchronization and acquires an Up Link (UL) parameter. Step S202, the terminal calculates a hash value of the AMS MAC Address, that is, the AMS MAC.

Address* ,

AMS MAC Address* = F (AMS MAC Address, ABSID, 48), or AMS MAC Address* = F (AMS MAC Address, Rand AMS, 48), or AMS MAC Address* = F (AMS MAC Address, Rand ABS, 48 ), or AMS MAC Address* = F(AMS MAC Address, ABSID|

Random_AMS, 48 ), or AMS MAC Address* = F(AMS MAC Address, Random AMS | AB SID,

48), or AMS MAC Address* = F(AMS MAC Address, ABSID| Random ABS , 48), or AMS MAC Address* = F(AMS MAC Address, Random ABS | ABSID ,

48), or AMS MAC Address* = F(AMS MAC Address, ABSID| Random AB S | Random AMS , 48) , or AMS MAC Address* = F(AMS MAC Address ,

Random AB S | Random AMS | ABSID, 48). Wherein, F can be any hash function, for example, Message-Digest Algorithm 5 (MD5) algorithm, Secure Hash Algorithm (SHA) algorithm, CMAC algorithm (Ciphertext packet link message) Authentication code), Dotl6KDF algorithm defined by IEEE 802.16, etc.; Random_ABS is a random number generated by the base station, and the random number is broadcasted by a mapping message (A-MAP), or when the terminal performs step S201, the base station allocates for the terminal, and CDMA_Allocation_IE (This information element is used by the base station to allocate bandwidth to the terminal, the terminal Sending a ranging request message to the base station on the bandwidth is sent to the terminal; Random_AMS is a random number generated by the terminal. Both Random_ABS and Random_AMS can be 16 bits, 32 bits, 48 bits, 64 bits, 128 bits, and the like. Step S203: The terminal sends an RNG-REQ message to the base station, where the RNG-REQ message carries the following parameters: AMS MAC Address * „Step S204, the base station sends an RNG-RSP message to the terminal, where the RNG-RSP message carries the parameter AMS. MAC address *, the parameter is used to identify which terminal the test 3 macro response message belongs to. Step S205, the terminal and the base station perform a pre-authentication capability negotiation process, and negotiate parameters required for the later authentication process. Step S206, the terminal and the network The authentication and authorization operations are performed on the side. Step S207: The terminal and the base station calculate the air interface key AK by using the AMS MAC Address*, and derive the CMAC KEY, and/or KEK from the AK. Step S208, the terminal and the network side perform a three-way handshake process, and verify Authorization key AK. Step 4: S209, the terminal and the base station generate a TEK for encrypting the data flow of the air interface. Step S210: The terminal sends a registration request message to the base station, where the registration request message optionally carries the parameter: AMS MAC Address, The registration request message needs to be encrypted and protected by the TEK. Step S211: The base station sends a registration response message to the terminal, where the registration response message carries the parameter: STI D. The transmission of the STID needs to be cryptographically protected. The subsequent message exchange process can use the STID to identify the terminal. Embodiment 3 FIG. 3 is a schematic diagram of generating an airborne derived key according to an embodiment of the present invention, as shown in FIG. For the generation method of AK, see the following formula:

AK <= Dotl6KDF (PMK, AMS MAC Address*) ABSID| "AK" , 160 ) where Dotl6KDF is an encryption algorithm function defined in IEEE 802.16. "|,, such as IEEE

802.16 definition, used to indicate cascading. AMS MAC Address* is the hash of the terminal MAC address. value. ABSID ^& station identification information. "', indicating that the content is a string, "AK" means the string corresponding to the letter combination of AK. "160" indicates the length of AK, the unit is bit. Refer to the related description in the background art: PMK can be derived by MSK It is concluded that the MSK is a key in the IEEE 802.16 specification, which is generated by the mobile station and the base station at both ends in the initial authentication process. It should be noted that in the embodiment of the present invention, the same symbol represents The same meaning.

The CMAC KEY U and CMAC KEY D are generated by the following formula: First, determine CMAC PREKEY U and CMAC PREKEY D, CMAC PREKEY U and CMAC PREKEY D to derive an intermediate parameter of CMAC KEY U and CMAC KEY D. Among them, CMAC_PREKEY_U and CMAC PREKEY D are generated as follows:

CMAC PREKEY U | CMAC PREKEY D <= Dotl6KDF ( AK, AMS MAC Address* | ABSID | "CMAC KEYS" , 256 ) „ where "CMACJ EYS" is the character string corresponding to the CMACJ EYS character combination. 256 means 4 dance The length of the result is 256 bits. The result of the above formula is the concatenation value of CMAC_PREKEY_U and CMAC PREKEY D, and the value of CMAC_PREKEY_U and CMAC PREKEY D is 128 bits before and after.

The CMAC PREKEY U and CMAC PREKEY D generation methods can also be implemented by: CMAC PREKEY U | CM AC PREKEY D| KEK < = Dotl6KDF ( AK,

AMS MAC Address*] ABSID] "CMAC KEYS +KEK" , 384 ) Different from the previous formula, this formula generates the key KEK together, and the generated result is taken three times 128 bits, which will correspond to CMAC PREKEY U, respectively. CMAC PREKEY D and KEK.

The CMAC KEY U and CMAC KEY D are generated as follows: CMAC KEY U <= AESCMAC PREKEY U ( CMAC KEY COUNT )

CMAC KEY D <= AESCMAC PREKEY D ( CMAC KEY COUNT ) where AES is the Advanced Encryption Standard algorithm. Through the above two equations, CMAC_KEY_U and CMAC_KEY_D can be determined. For the generation method of TEK, see the following formula:

TEK <= Dotl6KDF ( AK, SAID | AMS MAC Address*] COUNTER TEK I "TEK" , 128 ) where AK is the authorization key generated in the foregoing manner, COUNTER_TEK is a counter, and the counter is initialized or heavy at the terminal each time. Authentication Α 重置 is reset when authorized, and each pair is updated once, and the value is incremented by 1. The SAID is the SA identity, and is assigned by the base station to the mobile station. For the generation of this parameter, refer to the relevant provisions in IEEE 802.16m, which is not mentioned here. "TEK" means the string corresponding to the letter combination of TEK. 128 indicates that the length of the TEK is 128 bits. The way TEK is generated can also be achieved by:

TEK <= Dotl6KDF ( AK, SAID | COUNTER TEK | "TEK", 128 ). The meanings of the parameters in the formula are exactly the same as those in the aforementioned TEK generation formula, and are not mentioned here. In the fourth embodiment, when the terminal needs to perform handover between the base stations, the terminal sends the updated terminal MAC address security calculation value to the target base station. 4 is an interaction flowchart according to Embodiment 4 of the present invention. The specific operation is as shown in FIG. 4, and mainly includes the following steps S402 to S408: Step S402: The terminal sends a terminal handover command (AAI_HO_CMD) message to the current serving base station, In order to notify the monthly base station, the terminal needs to switch to the target base station. Step S404: The serving base station performs a handover confirmation message interaction process with the target base station, and confirms to the target base station that the terminal is about to switch. Step S406, the terminal calculates a security calculation value (AMS MAC Address*) of the updated terminal MAC address, and sends a ranging request (RNG-REQ) message to the target base station, where the message carries the parameter: AMS MAC Address*, step S408, target The base station sends a measurement macro response (RNG-RSP) message to the terminal. Embodiment 5 This embodiment shows that a terminal transmits a terminal MAC address to a target base station when performing handover. Another method, FIG. 5 is an interaction flowchart of Embodiment 5 of the present invention. As shown in FIG. 5, the method includes the following steps S502 to S508: Step S502: Before the terminal sends a handover command message to the base station, calculate the terminal MAC address. The security calculation value is sent to the serving base station in the handover indication message. Step S504: The serving base station performs a handover confirmation message interaction process with the target base station, and confirms to the target base station that the terminal is about to switch. In the process, the monthly base station transmits the security calculation value of the terminal MAC address to the target base station. Step S506: The terminal sends a ranging request (RNG-REQ) message to the target base station. Step S508, the target base station sends a measurement response (RNG-RSP) message to the terminal. In the sixth embodiment, when the terminal needs to perform the location update or the Idle mode, the terminal sends the updated terminal MAC address security calculation value to the base station. FIG. 6 is an interaction flowchart of the sixth embodiment of the present invention, as shown in FIG. The method mainly includes the following steps S602 to S604: Step S602, when the Idle mode re-entry network trigger condition is satisfied, the terminal calculates a security calculation value of the terminal MAC address, and sends a ranging request message to the base station. The message carries parameters: a secure calculated value of the terminal MAC address. Step S604: The base station sends a ranging response message to the terminal. Embodiment 7 This embodiment provides a protection device for terminal privacy. FIG. 7 is a structural block diagram of a device for protecting privacy of a terminal according to an embodiment of the present invention. As shown in FIG. 7, each module of the device is disposed on both sides of the base station 4 and the terminal 6, wherein the base station 4 side includes: The receiving module 42 and the first calculating module 44 are described below. The first receiving module 42 is disposed on the side of the base station 44, and is configured to receive a ranging request message from the terminal 6 when the terminal 6 initially enters the network or re-enters the network, where the ranging request message carries the media connection calculated by the terminal 6. The security calculation value of the control address is used to protect the real terminal media access control address and identify the terminal 6; the first calculation module 44 is connected to the first receiving module 42 and is disposed on the base station 4 side for After the terminal 6 successfully completes the authentication/authorization, the first reception is used. The security calculation value received by module 42 calculates the air interface key. FIG. 8 is a block diagram of a preferred structure of a device for protecting privacy of a terminal according to an embodiment of the present invention. As shown in FIG. 8, the base station 4 includes: a first sending module 46, a second receiving module 48, and the terminal 6 includes: a second computing module 62. The second sending module 64 and the third calculating module 66. The foregoing structure is described below. The first sending module 46 is disposed on the base station 4 side, and is configured to send a ranging response message to the terminal 6, and carry a security calculation value therein to indicate that the ranging response message belongs to the terminal 6; the second receiving module 48 is disposed at the base station 4. The side is configured to receive a registration request message from the terminal 6, where the registration request message carries the media access control address of the terminal 6, and the registration request message is encrypted by the terminal 6 according to the air interface key. The second calculation module 62 is disposed on the terminal 6 side for calculating a security calculation value of the media access control address. The second sending module 64 is connected to the second calculation module 62 and is disposed on the terminal 6 side for the base station 4 Sending a ranging request message carrying the security calculation value calculated by the second calculation module 62; the third calculation module 66 is connected to the second calculation module 62, and is disposed on the terminal 6 side for security calculated by using the second calculation module 62. Calculate the value to calculate the air interface key. In summary, the foregoing embodiment of the present invention provides a protection scheme for terminal privacy. When the terminal initially enters the network or re-enters the network, the terminal calculates a security operation value of the terminal MAC address, and secures the terminal MAC address. The calculated value is sent to the base station in the ranging request message. After the terminal successfully completes the authentication authorization, the terminal and the network side calculate the relevant air interface key by using the terminal MAC address security calculation value when calculating the derived key of the air interface, and solve the terminal privacy defined by 802.16m (AMS Privacy). There is no problem in solving the risk caused by the AMS MAC Address plaintext transmission, which improves the security of the system. Obviously, those skilled in the art should understand that the above modules 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, or they may be separately fabricated into individual integrated circuit modules, or they may be Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above description is only a preferred embodiment of the present invention, and is not limited to the IEEE 802.16 system. Its associated mode can be applied to other wireless communication systems. It will be apparent to those skilled in the art that various modifications and changes can be made in 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.

Claims

Claim

A method for protecting terminal privacy, characterized in that it comprises:

When the terminal initially enters the network or re-enters the network, the base station receives the ranging request message from the terminal, where the ranging request message carries the security calculation value of the media access control address calculated by the terminal, The security calculation value is used to protect the real terminal media access control address and identify the terminal;

After the terminal successfully completes the authentication authorization, the base station calculates the air interface key using the security calculation value.

The method according to claim 1, wherein before the receiving, by the base station, the ranging request message from the terminal, the method further includes:

The terminal calculates the security calculation value of the media access control address, and sends a measurement request message to the base station.

3. The method of claim 2, wherein the terminal calculates the security calculation value of the media access control address according to a terminal media access control address and at least one of:

The random number generated by the terminal, the random number generated by the base station, and the base station identifier.

The method according to claim 1, wherein after the base station receives the ranging request message from the terminal, the method further includes:

The base station sends a ranging response message to the terminal, and carries the security calculation value therein to indicate that the ranging response message belongs to the terminal.

The method of claim 1, wherein after the terminal successfully completes the authentication/authorization, the method further includes:

The terminal calculates the air interface key using the security calculation value.

The method according to claim 1, wherein after the base station calculates the air interface key by using the security calculation value, the method further includes: The base station receives a registration request message from the terminal, where the registration request message carries the media access control address of the terminal, and the registration request message is received by the terminal according to the air interface. The key is encrypted.

The method according to claim 1, wherein when the terminal needs to perform handover between base stations, the base station serves as a target base station for handover by the terminal, and the target base station receives the terminal from the terminal. The ranging request message, where the ranging request message carries the security calculation value.

The method according to claim 1, wherein when the terminal needs to perform handover between base stations, and the base station serves as a target base station for handover by the terminal, the target base station receives the terminal The security calculation value sent in the handover command message via the serving base station.

The method according to claim 1, wherein the base station receives a ranging request message from the terminal when the terminal performs the exiting the idle mode re-entry network, where the ranging request message is Carrying the safety calculation value.

The method according to any one of claims 1 to 9, wherein the security calculation value comprises at least one of the following:

The hash value and the encrypted operation value, wherein the hash value is calculated according to one of the following algorithms: a credit abstraction algorithm, a secure hash algorithm, a ciphertext packet link message authentication code algorithm, and a Dotl6KDF algorithm.

The method according to any one of claims 1 to 9, wherein the air interface key comprises at least one of the following:

Authorization key, message integrity protection key, transport encryption key, key encryption key.

12. A terminal privacy protection device, comprising:

a first receiving module, configured on the base station side, is configured to receive a ranging request message from the terminal when the terminal initially enters the network or re-enters the network, where the ranging request message carries the media calculated by the terminal a security calculation value of the access control address, where the security calculation value is used to protect a real terminal media access control address and identify the terminal;

The first computing module is configured to be configured on the base station side, and configured to calculate an air interface key by using the security calculation value received by the first receiving module after the terminal successfully completes the authentication/authorization.

13. The device according to claim 12, further comprising:

a first sending module, configured to send a ranging response message to the terminal, and carry the security calculation value to indicate that the ranging response message belongs to the terminal; the second receiving module, setting a base station side, configured to receive a registration request message from the terminal, where the registration request message carries the media access control address of the terminal, where the registration request message is used by the terminal The air interface key is encrypted;

a second calculation module, configured to be configured to calculate the security calculation value of the media access control address, where the second sending module is configured to send a ranging request message to the base station; And a third calculation module, configured on the terminal side, configured to calculate the air interface key by using the security calculation value.