WO2009149666A1 - Method, device and system for negotiating algorithm - Google Patents

Abstract

A method for negotiating algorithm is disclosed. According to the method, the network side acquires the information of the algorithm which is supported by the User Equipment (UE) for computing the secret key KASME. The algorithm is selected according to the information of the algorithm supported by both the UE and the Home Subscriber Server (HSS). The selected algorithm is used as the algorithm for computing the secret key KASME between the UE and the HSS. As a result, the negotiation of the algorithm for computing the secret key is enabled between the HSS and the UE. A device and a system for negotiating algorithm are also disclosed.

Description

 Method, device and system for algorithm negotiation

 [1] This application requires a Chinese patent application filed on September 12, 2008, with the application number 200810160852.1, the invention titled "Methods, Devices and Systems for Algorithm Negotiation", and submitted on June 13, 2008. Priority is claimed on Chinese Patent Application No. 200810067758.

[2] Technical field

 [3] The present invention relates to wireless communication technologies, and in particular, to a method, apparatus, and system for algorithm negotiation.

 [4] Background of the invention

 [5] 3GPP (Third Generation Partnership Project

 The 3rd Generation Partnership Project) defines a third-generation wireless communication network technology standard UMTS (Univers al Mobile Telecommunication System

 Universal Mobile Telecommunications System). In order to ensure the competitiveness of 3GPP in the future, in 3GPP, various vendors are actively studying EPS (Evolved Packet System).

[6] In the key architecture of the EPS network, USIM (UMTS Subscriber Identity Module UMTS User Identification Card) and Network Side AuC (Authentication Centre)

 Authentication Center) Shared Key K; USIM and AuC derive keys CK and IK based on shared key Κ; Au C sends CK and IK to HSS (Home Subscriber Server Home Client Server). UE (User Equipment

 User equipment) and HSS derive KASME based on CK and IK. The algorithm for deriving KASME between UE and HSS is the default. The algorithm that deduces KASME is also referred to as the key deduction algorithm.

[7] In the process of implementing the present invention, the inventors found that at least the following problems exist in the prior art: With HSS and

UE upgrades, HSS and UEs produced by different manufacturers may support a variety of more secure algorithms for deriving KASME. However, in the prior art, the algorithm for deriving KASME between UE and HSS is the default, so it is difficult to meet multiple types of support. The need for a key deduction algorithm.

[8] Summary of the invention

[9] The embodiment of the invention provides a method, device and system for algorithm negotiation, so that the HSS and the user equipment The key derivation algorithm used by both can be negotiated.

 [10] The embodiment of the present invention discloses a method for algorithm negotiation, which includes: acquiring, by a network side, information about an algorithm for deriving a key KASME supported by a user equipment; and supporting the user equipment and the home client server HSS. Algorithm information, selection algorithm; The selected algorithm is used as an algorithm for deriving the key KASME between the user equipment and the HSS.

 [11] The embodiment of the present invention discloses a network side device, including: a transceiver unit, configured to acquire information about an algorithm for deriving a key KASME supported by a user equipment; and a selecting unit, configured to use the user equipment and the attribution The information of the algorithm that the client server HSS can support, select the algorithm, and use the selected algorithm as the algorithm for deriving the key KASME between the user equipment and the HSS.

 [12] The embodiment of the present invention discloses a user equipment negotiated by an algorithm, including: a transceiver unit, configured to send, to a network side device, information about an algorithm for deriving a key KASME supported by the user equipment, and receiving the foregoing Information about the selected algorithm sent by the network side device after selecting the algorithm.

 [13] The embodiment of the present invention discloses a network side device negotiated by an algorithm, including: a transceiver unit, configured to acquire information about an algorithm for deriving a key KASME supported by a user equipment; and a selecting unit, configured to be used according to the user The device and the information of the algorithm that the home server HSS can support, select an algorithm; and use the selected algorithm as an algorithm for deriving the key KASME between the user equipment and the HSS.

 [14] The embodiment of the present invention discloses a system for negotiating an algorithm, including: a user equipment: configured to send, to a network side device, information about an algorithm for deriving a key KASME supported by the user equipment, and receive the network side. The information of the selected algorithm sent by the device after selecting the algorithm; the network side device: used to obtain the information of the algorithm for deriving the key KASME supported by the user equipment, and perform algorithm selection according to the information of the algorithm that the user equipment can support And send the information of the selected algorithm to the user equipment.

[15] The embodiment of the present invention discloses a system for negotiating an algorithm, which can communicate with a user equipment, including: an HSS and an MME, where: an HSS is used to obtain an authentication data request message sent by the MME to obtain a support that the user equipment can support. The information of the algorithm is selected according to the information of the algorithm used by the user equipment and the HSS to derive the key KASM E, and the information of the selected algorithm is sent to the MME through the authentication data response message; the MME is used to Acquiring information of an algorithm for deriving the key KASME supported by the user equipment, and transmitting information of an algorithm for deriving the key KASME supported by the user equipment to the attachment or location update request of the user equipment forwarded by the base station HSS; and after the HSS selection algorithm, The information of the selected algorithm is received, and the information of the selected algorithm is sent to the user equipment by the base station.

 [16] By comparison, it can be found that any one of the above technical solutions has the following advantages or benefits compared with the prior art:

 [17] In the embodiment of the present invention, the information about the algorithm for deriving the key KASME supported by the user equipment is obtained by the network side; and the algorithm is selected according to the information of the algorithm supported by the user equipment and the home client server HSS; The selected algorithm is used as an algorithm for deriving the key KASME between the user equipment and the HSS; thus, the algorithm is negotiated between the HSS and the user equipment, which is convenient for flexible selection of the key derivation algorithm.

[18] BRIEF DESCRIPTION OF THE DRAWINGS

 FIG. 1 is a flowchart of a method for algorithm negotiation according to an embodiment of the present invention; FIG.

 2 is a flowchart of a method for negotiating an algorithm according to Embodiment 1 of the present invention;

 FIG. 3 is a flowchart of a method for negotiating an algorithm according to Embodiment 2 of the present invention; FIG.

 [22] FIG. 4 is a schematic diagram of a manner in which an HSS sets a selected algorithm in an AV according to Embodiment 2 of the present invention;

 FIG. 5 is a flowchart of a method for negotiating an algorithm according to Embodiment 3 of the present invention; FIG.

 6 is a flowchart of a method for negotiating an algorithm according to Embodiment 4 of the present invention;

 FIG. 7 is a network architecture diagram of an application scenario according to Embodiment 5 of the present invention; FIG.

 FIG. 8 is a diagram showing an algorithm negotiation system and apparatus according to an embodiment of the present invention; FIG.

 FIG. 9 is a diagram showing another algorithm negotiation system and apparatus according to an embodiment of the present invention; FIG.

 FIG. 10 is a schematic diagram of a network side device provided by an embodiment of the present invention.

 [29] Mode for carrying out the invention

 [30] In order to make the objects, the technical solutions and the advantages of the present invention more comprehensible, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

 An embodiment of the present invention provides a method for algorithm negotiation, which specifically includes:

 [32] Step a: The network side obtains information about an algorithm for deriving the key KASME that the user equipment can support;

[33] Step b. Select an algorithm based on the information of the algorithm supported by the user equipment and the home client server HSS;

 [34] Step c. The selected algorithm is used as an algorithm for deriving the key KASME between the user equipment and the HSS.

[35] The embodiment of the present invention provides a method for algorithm negotiation, as shown in FIG. 1: [36] In step 101, the HSS acquires information about an algorithm that the user equipment can support;

 [37] In step 102, the HSS selects an algorithm according to information of an algorithm that the user equipment can support;

 [38] In step 103, the HSS transmits information of the selected algorithm to the user equipment.

 [39] The information of the above algorithm may specifically be information for deriving the algorithm of KASME. HSS can pass MM E (Mobility Management Entity

 The mobility management entity) and the base station acquire information of a key derivation algorithm supported by the user equipment and transmit information of the selected algorithm.

 [2] FIG. 2 is a flowchart of a method for negotiating an algorithm according to Embodiment 1 of the present invention, including:

[41] Step 201: The UE sends an Attach/TAU to the eNB (eNodeB evolved base station)

 Request (attach / location update request), in the Attach/TAU

 The Request carries the information of the key derivation algorithm supported by the UE.

[42] The specific carrying method can be: Due to Attach/TAU

 Request carries the temporary identity of the UE, such as UE Network

 Information such as Capability (the network capability of the UE), so it can carry U in the network capability information of the UE.

Information supported by the key deduction algorithm supported by E.

[42] Step 202: After receiving the Attach/TAU Request, the eNB forwards the message to the MME.

[44] Step 203, MME decides to trigger AKA (Authentication and Key Agreed)

 Authentication and key agreement) process.

[45] Step 204: During the execution of the AKA, the MME sends an Authentication Data to the HSS.

 Request (authentication data request), in the Authentication Data

 The Request carries the information of the key derivation algorithm supported by the UE.

[46] The Authentication Information Request sent by the MME to the HSS includes a Requesting Node.

Type of IE (information Element

 Information element). The IE is mainly used to indicate the type of the node requesting the authentication vector, such as: MME, SG SN, MME/SGSN, and the like. The IE may be extended, for example, by extending 4 bits to represent an algorithm supported by the UE, for example: 0001 indicates support algorithm 1, 0011 indicates support algorithm 1 and algorithm 2, 0111 indicates support algorithm 1, algorithm 2, algorithm 3, and 1111 indicates support Algorithm 1, Algorithm 2, Algorithm 3, and Algorithm 4 are four algorithms.

[47] It should be specially noted that the above algorithm 1, algorithm 2, algorithm 3, and algorithm 4 represent four different types of support. The algorithm is merely an example for the convenience of understanding, and the scope of application of the embodiments of the present invention cannot be limited. That is, the type and name of the above algorithm may not be used in some systems, but the present invention cannot be considered as implemented. The technical solutions in the examples are not applicable to these systems.

 [48] Step 205: The HSS selects a key deduction algorithm supported by the user equipment.

 [49] Step 206: In the process of performing the AKA, the information of the algorithm selected in step 205 is sent to the MME through an Authentication Data Response message.

[50] Step 207: After receiving the authentication data response sent by the HSS, the MME performs a subsequent AKA process with the UE.

[51] Step 208: After the AKA process is successful, a NAS (Non-Access Stratum non-access stratum) SMC (Security Mode Command) is established between the MME and the UE.

 Safe mode command) process. The MME sends the NAS to the UE through the eNB.

 The SMC message carries the information of the key deduction algorithm selected by the HSS in the message.

[52] Step 209: After receiving the NAS SMC message of the MME, the eNB establishes RRC (Radio Resource) with the UE.

Control radio resource control) bearer, NAS over RRC bearer

 SMC message is forwarded to the UE; UE is sent from the NAS

 The information of the key deduction algorithm selected by the HSS is obtained in the SMC message.

[53] It is worth mentioning that: Since the eNB may tamper with the UE's algorithm, it is necessary to transmit the algorithm supported by the UE from the network side to the UE for verification. The method of returning may be: In step 208, the MME puts the algorithm supported by the UE received in step 202 into the NAS.

 The SMC message is transmitted to the UE; or, in step 205, the HSS utilizes AMF (Authentication Management Field) in the AV (Authentication Vector Authentication Vector)

 Any 4 bits in the authentication management domain) indicates the algorithm supported by the UE received from the MME in step 204, and is transmitted to the UE through step 206 and step 207.

[54] The above AMF is AUTN (Authentication token) in AV (Authentication Vector)

 Authentication token) The included authentication management domain, which is sent to the M in the authentication data response included in step 206.

[55] In this embodiment, the UE reports the information of the supported key deduction algorithm to the HSS, and the HSS selects from the foregoing algorithm and feeds back to the UE, thereby establishing an algorithm negotiation mechanism between the UE and the HSS. Achieved The flexible selection of the key derivation algorithm, and the modification of the uplink interface protocol between the MME and the HSS in the prior art is small.

FIG. ₃ is a flowchart of a method for negotiating an algorithm according to Embodiment 2 of the present invention. The main difference from Embodiment 1 is: HSS uses different key derivation algorithms to carry information of a selected algorithm. . Specifically include:

 Steps 301, 302, 303, and 304 are the same as steps 201, 202, 203, and 204 in Embodiment 1, respectively.

, no longer praise here.

 Step 305: After the HSS selects a key deduction algorithm supported by the UE, the information that the AV carries the selected algorithm to specifically carry the information of the selected algorithm may be: one or several bits of the AMF included in the AUTN in the AV. To represent the information of the selected algorithm.

 At present, AMF has 16bit, and the 0th position has been specified as separation.

Bit (separated bit), the set of this bit indicates the AV of the SAE, the remaining 1 to 7 bits are the standardized reserved bits, and the 8 to 15 bits are used for the purpose of proprietary (private). Therefore, some of the 8 to 15 bits can be selected to represent the key derivation algorithm. The HSS indicates the information of the selected algorithm by setting these algorithms. The following is an example:

 FIG. 4 is a schematic diagram showing a manner in which an HSS sets a selected algorithm in an AV in step 305 according to Embodiment 2 of the present invention, including: Suppose the UE supports four key deduction algorithms A, B, C, and D for HSS. The selection, and the HSS convention are represented by 00, 01, 10, and 11 respectively; after the HSS selects among the four algorithms, the selected algorithm is recorded in the AMF in a set manner. For example: If HSS selects algorithm A, you can choose to set the 14th and 15th bits of AMF to 0 and 0 respectively to indicate the result of selection. If HSS sets bits 14 and 15 to 0 and 1, respectively, it means selecting Algorithm B.

 It should be specially pointed out that: The HSS may also agree with other representation methods of the UE according to factors such as the number of algorithms of the UE, or select one or more other AMFs to carry the selection result.

 Step 306: During the execution of the AKA, the HSS sends the AV carrying the information of the selected algorithm to the MME through an Authentication Data Response message.

Step 307: During the subsequent AKA process, the MME and the eNB forward the AV to the UE, and the UE passes the A. [65] It should be particularly noted that FIG. 4 referred to in Embodiment 2 of the present invention is a case where the HSS indicates a selected algorithm by setting, and is merely an example for convenience of understanding. The types and names of the UE algorithms in FIG. 4, such as B, C, D, 00, 01, 10, 11 and the like, cannot limit the scope of application of the embodiments of the present invention, that is, in some systems, the above algorithms may not be used. Kind and name, however, it cannot be considered that the technical solutions in the embodiments of the present invention are not applicable to these systems.

 [66] It is worth mentioning that: Since the eNB may tamper with the UE's algorithm, it is necessary to transmit the algorithm supported by the UE from the network side to the UE for verification. The method of returning is substantially the same as that of Embodiment 1, and will not be described here.

 [67] In this embodiment, the HSS uses the information of the selected algorithm to be represented by some bits of the AMF, and is carried in the AUTN and sent to the user equipment, fully utilizing the existing resources, and implementing flexible selection of the key derivation algorithm. In the same way, by setting the AMF, the HSS informs the UE of the selected algorithm, and the method has less modification to the downlink protocol.

 FIG. 5 is a flowchart of a method for negotiating an algorithm according to Embodiment 3 of the present invention. The main difference from Embodiment 1 is that: MME decides which key derivation algorithm to specifically select. Specifically include:

[69] Steps 501, 502 are the same as steps 201 and 202 in Embodiment 1, and are not mentioned here.

[70] Step 503: The MME decides to perform AKA, and selects according to an algorithm supported by the UE and the HSS and a local policy.

Algorithms supported by UE and HSS.

[71] It should be noted that the method for the MME to learn the algorithm supported by the HSS may be: Configuring on the MME in advance

It is also possible that the HSS reports the supported algorithm to the MME by using a newly added message before the step 503.

[72] The above local policy may be: The MME selects one of the most secure algorithms from the algorithms supported by both the UE and the HSS.

 [73] Step 504: The MME sends an authentication data request carrying the algorithm selected in step 503 to the HSS.

 [74] Step 505: The HSS derives the KASME from CK and IK according to the algorithm selected by the MME, and sends an Authentication Data Response message to the MME.

[75] The KASME that HSS can perform can be carried in the Authentication Data Response.

[76] Step 506: After receiving the authentication data response sent by the HSS, the MME performs a subsequent AKA process with the UE.

 Step 507: After the AKA process is successful, a NAS (Non-Access Stratum non-access stratum) SMC (Security Mode Command) is established between the MME and the UE.

Safe mode command) process. The MME sends the NAS to the UE through the eNB. The SMC message carries the information of the selected key deduction algorithm in the message.

[78] Step 508: After receiving the NAS SMC message of the MME, the eNB establishes an RRC (Radio Resource Control) bearer with the UE, and uses the RRC bearer to connect the NAS.

 The SMC message is forwarded to the UE; the UE obtains information of the selected key deduction algorithm from the NAS SMC message.

[79] It is worth mentioning that: Because the eNB may tamper with the UE algorithm, in step 507, the MME needs to return the algorithm supported by the UE from the network side to the UE for verification. The method of the backhaul is substantially the same as the method in which the MME returns the algorithm supported by the UE in Embodiment 1, and is not mentioned here.

[80] In this embodiment, the MME selects an algorithm for deriving the key KASME between the UE and the HSS according to a key deduction algorithm supported by the UE and the HSS, thereby establishing an algorithm negotiation mechanism between the UE and the HSS. A flexible selection of the key deduction algorithm is implemented.

6 is a flowchart of a method for algorithm negotiation according to Embodiment 4 of the present invention, which mainly relates to an algorithm negotiation method between a UE and an HSS in an EPS inter-network handover scenario. Specifically include:

[82] Step 601: The source eNB in the network where the UE is currently located decides to perform handover.

[83] Step 602: The source eNB sends a Handover Required to the source MME.

[84] Step 603: The source MME sends a Forward Relocation to the target MME in the handover target network.

 Request (forwarded relocation request), carrying the information of the UE's key deduction algorithm.

[85] The Forward Relocation

 The Request includes the security capability of the UE, and the security capability of the UE may include a key deduction algorithm supported by the UE.

 [86] Optionally, the source MME may notify the target MME of the algorithm supported by the HSS by using the message.

 [87] Steps 604-610, completing the subsequent handover process. among them:

 [88] Step 604: The target MME sends a handover request to the target eNB.

 [89] Step 605: The target eNB sends a handover request response to the target MME.

 [90] Step 606: The target MME forwards the relocation response to the source MME.

 [91] Step 607: The source MME sends a handover command to the source eNB.

 [92] Step 608: The source eNB sends a handover command to the UE.

 [93] Step 609: The UE performs handover confirmation to the target eNB.

[94] Step 610: The target eNB sends a handover announcement to the target MME. [95] Step 611: After the handover succeeds, the UE sends a TAU (Tracking Area Update Location Update) request to the target eNB.

 [96] Step 612: The target eNB forwards the TAU request to the target MME.

 [97] Step 613: The target MME decides to perform an AKA authentication process; the target MME selects an algorithm from the algorithms supported by the UE and the HSS according to the local policy.

 [98] Since the target MME has learned the algorithm supported by the UE in step 603, if the target MME further obtains the HSS-supported algorithm from step 603, the target MME may select a UE and an HSS-supported algorithm according to the local policy. . If the target MME does not obtain the HSS-supported algorithm from the source MME in step 603, the method for the target MME to learn the algorithm supported by the HSS may be: configured on the target MME in advance, or may be newly added by the HSS before step 613. The message reports the supported algorithm to the target MME.

 [99] Step 614: The target MME sends an authentication data request to the HSS. The authentication data request also includes an algorithm selected by the target MME. gP, the target MME informs the HSS of the algorithm selected in step 613 by this message.

 [100] Step 615: The HSS derives the KASME from the CK and the IK according to the algorithm selected by the target MME, and sends an Authentication Data Response message to the target MME.

[101] Step 616: Perform a subsequent AKA authentication process between the target MME and the UE.

 [102] Step 617: After the AKA process is successful, a NAS (Non-Access) is established between the target MME and the UE.

 Stratum non-access layer) SMC (Security Mode Command

 Safe mode command) process. The target MME sends the NAS to the UE through the target eNB.

 The SMC message carries the information of the selected key deduction algorithm in the message.

[103] Step 618: The target eNB receives the NAS of the target MME.

 After the SMC message, the RRC bearer is established with the UE, and the NAS is carried over by the RRC bearer.

 The SMC message is forwarded to the UE; the UE obtains information of the selected key deduction algorithm from the NAS SMC message.

[104] It is worth mentioning that: Since the eNB may tamper with the UE algorithm, in step 617, the target MME needs to transmit the algorithm supported by the UE from the network side to the UE for verification. The method of returning and the MM in the first embodiment

The method of E backhauling the algorithms supported by the UE is roughly the same, and will not be mentioned here.

[105] In this embodiment, the MME participates in the algorithm selection, and the UE and the HSS are implemented in the handover scenario between the EPS networks. The problem between the algorithm negotiation.

 [106] The algorithm negotiation method provided by Embodiment 5 of the present invention mainly relates to a key deduction algorithm negotiation method between a UE and an HSS in an EPS to 2G/3G network handover scenario.

 [107] In the 2G/3G system, it is possible that the operator has no time to upgrade the HLR (Home Location Register) to the HSS function, so the IWF (Interworking Function Interworking Function Unit) is used to implement the HLR and EPS system. Interworking, that is, the IWF and the HLR are combined to function as H SS. In this case, the key derivation algorithm negotiation between the UE and the HSS is performed between the UE and the IWF representing the HSS part function, and the IWF implements the derivation of CK/IK to KASME. The network architecture is shown in Figure 7. Specific algorithm negotiation methods include:

 [108] The IWF and the UE respectively report the algorithms supported by the UE to the MME, and the reporting method is similar to the process in which the HSS and the UE report the algorithm to the MME in Embodiment 3, and the main difference is that the IWF is used instead of the HSS to perform the algorithm negotiation function. Then, the MME determines an algorithm between the UE and the IWF according to the local policy, and notifies the UE to the UE and the IWF, and the notification process is the same as the method in which the MME in the third embodiment informs the UE and the HSS after selecting the algorithm.

 In this embodiment, in order to avoid the eNB tampering with the UE, the MME may return the algorithm supported by the UE from the network side to the UE for verification. The method of the backhaul is substantially the same as the method in which the MME returns the algorithm supported by the UE in Embodiment 1, and is not mentioned here.

 [110] This embodiment solves the problem of the negotiation of the key derivation algorithm between the UE and the HSS in the EPS to 2G/3G network handover scenario.

 [111] It will be understood by those skilled in the art that all or part of the steps in the foregoing embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and the storage may be performed. The medium can be ROM/RAM, disk, CD, etc.

 It will also be understood that, although the above description uses sequential descriptions of the steps of the method for ease of understanding, it should be noted that the order of the above steps is not strictly limited.

FIG. 10 is a schematic diagram of a network side device provided by an embodiment of the present invention. The network side device specifically includes a transceiver unit 1001 and a selection unit 1002. The transceiver unit 1001 is configured to obtain information about an algorithm that can be used by the user equipment to derive the key KASME. The selecting unit 1002 is configured to select an algorithm according to information about an algorithm that the user equipment and the home client server HSS can support; And the selected algorithm An algorithm for deriving the key KASME between the user equipment and the HSS.

[114] The network side device may be an HSS or an MME.

 [115] When the network side device is an HSS, the transceiver unit 1001 is further configured to send an algorithm selected by the selecting unit 1002 to the UE.

 [116] When the network side device is the MME, the transceiver unit 1001 is further configured to acquire algorithm information supported by the HSS, and send the algorithm selected by the selecting unit 1002 to the UE and the HSS, respectively.

 [117] The following describes an embodiment of a mobile communication system according to an embodiment of the present invention. The system can implement the steps as described in the foregoing method embodiments. It can be understood that the system in the embodiment of the present invention may further include implementing communication. For the other embodiments of the present invention, the details are not mentioned in the embodiment of the present invention. The main part of the system. Referring to Figure 8, the system 80 includes a user equipment 81 and a network side device HSS 82 in communication therewith, where:

 [118] The user equipment 81 includes a transceiver unit 811 for the network side device HSS

 82 transmitting information of an algorithm supported by the user equipment, and receiving the HSS

 82 Information of the selected algorithm sent after the algorithm is selected.

 [119] Network side equipment HSS

 82 includes a transceiver unit 821 and a selection unit 822, wherein the transceiver unit 821 is configured to acquire information about an algorithm supported by the user equipment 81, and send information of the algorithm selected by the selection unit 822 to the user equipment 81; The algorithm is selected according to the information of the algorithm that the user equipment 81 can support; the selecting unit 822 can be further configured to set the information of the selected algorithm to the authentication vector AV in a set manner.

 The transceiver unit 821 can obtain the information of the algorithm supported by the user equipment by using the authentication data request message sent by the MME, and send the information of the algorithm selected by the selecting unit 822 to the MME through the authentication data response message.

 FIG. 9 is a schematic diagram of another system 90 according to an embodiment of the present invention. The system 90 includes a user equipment 91 and a network side device MME 92 communicating therewith, where:

[122] The user equipment 91 includes a transceiver unit 911 for the network side device MME

92 transmitting information of an algorithm that the user equipment can support, and receiving the MME 92 Information of the selected algorithm sent after the algorithm is selected.

[123] Network side device MME

 92 includes a transceiver unit 921 and a selection unit 922, wherein the transceiver unit 921 is configured to acquire information about the algorithm supported by the user equipment 91 and the HSS, and send information of the algorithm selected by the selection unit 922 to the HSS and the user equipment 91; The selection unit 922 is configured to select an algorithm based on information of an algorithm that the user equipment 91 can support.

 [124] It will be understood that the structures shown in the drawings are merely schematic, and represent logical structures in which the units displayed as separate components may or may not be physically separated, and the components displayed as units may Yes or may not be a physical unit, that is, it can be located in one place or distributed to several network units.

 The drawings and the related description are merely illustrative of the principles of the invention and are not intended to limit the scope of the invention. For example, the message names in various embodiments of the present invention may vary depending on the network, and some messages may be omitted. Therefore, any modifications, equivalents, improvements, etc. made within the spirit and scope of the present invention are included in the scope of the present invention.

The present invention has been illustrated and described with reference to the preferred embodiments of the present invention, and those skilled in the art The spirit and scope of the invention are not departed.

Claims

Claim  [1] A method for algorithm negotiation, which is characterized by comprising:  Obtaining, by the network side, information about an algorithm for deriving the key KASME supported by the user equipment; and selecting an algorithm according to information about an algorithm for deriving the key KASME supported by the user equipment and the home client server HSS;  Using the selected algorithm as an algorithm for deriving the key KASME between the user equipment and the HSS [2] The method according to claim 1, wherein the network side acquires information of an algorithm supported by the user equipment for deriving the key KASME, according to which the user equipment and the HSS can support For the information of the algorithm for deriving the key KASME, the selection algorithm includes:  The HSS acquires, by the mobility management entity MME and the base station, information about an algorithm that the user equipment can support for deriving the key KASME;  The HSS selects an algorithm based on information of the algorithm that the user equipment and the HSS can use to derive the key KASME.  [3] The method according to claim 2, wherein the information that the HSS obtains, by the MME and the base station, the algorithm for deriving the key KASME supported by the user equipment, specifically includes: Obtaining, in the authentication data request message sent by the MME, information about an algorithm that the user equipment can support for deriving the key KASME;  And/or, the MME acquires, from the attachment or location update request of the user equipment that is forwarded by the base station, information about an algorithm that the user equipment can support for deriving the key KASME. [4] The method of claim 2, further comprising:  The HSS sends information of the selected algorithm to the user equipment through the MME and the base station. [5] The method according to claim 4, wherein the transmitting, by the MME and the base station, the information of the selected algorithm to the user equipment by using the MME and the base station, specifically:  Sending, by the HSS, an authentication data response message to the MME, where the authentication data response message includes information of the selected algorithm; And/or, the MME sends a non-access stratum security mode command NAS SMC to the user equipment by using the base station, where the non-access stratum security mode commands NAS The SMC contains information about the selected algorithm. [6] The method according to claim 2, wherein the information of the selected algorithm uses an authentication vector  Authentication token in AV The AUTN contains one or more digits of the authentication management domain AMF. [7] The method of claim 6, further comprising:  The HSS transmits an AV containing information of the selected algorithm to the user equipment through the MME and the base station in the process of performing authentication and key agreement AKA. [8] The method according to claim 1, wherein the network side acquires information of an algorithm for deriving the key KASME supported by the user equipment, according to what the user equipment and the HSS can support. For the information of the algorithm for deriving the key KASME, the selection algorithm includes:  The MME obtains information about an algorithm supported by the HSS;  The MME selects an algorithm based on an information method supported by the user equipment and the HSS for deriving the key KASME. [9] The method according to claim 1, further comprising:  The network side sends back information of the algorithm for deriving the key KASME supported by the user equipment to the user equipment for verification. [10] A network side device, comprising:  Transceiver unit: used to obtain information of an algorithm supported by the user equipment for deriving the key KASME;  Selection unit: for selecting information based on information of an algorithm for deriving the key KASME supported by the user equipment and the home client server HSS; and selecting the selected algorithm as the user equipment and H The algorithm used to derive the key KASME between SSs. [11] The network side device according to claim 10, wherein the network side device is specifically an HSS or a mobility management entity MME. [12] The network side device according to claim 11, wherein  The network side device is an HSS port. The transceiver unit is configured to acquire information about an algorithm that can be supported by the user equipment by using an authentication data request message sent by the MME, and configured to send, by using an authentication data response message, the information of the algorithm selected by the selecting unit to the MME. [13] The network side device according to claim 11, wherein  The network side device is an HSS port.  The selecting unit is further configured to set the information of the selected algorithm to the authentication vector AV in a set manner;  The transceiver unit is configured to acquire information about an algorithm that can be supported by the user equipment by using an authentication data request message sent by the MME, and configured to send, by using an authentication data response message, the AV that includes the information of the selected algorithm to the MME. [14] A method for algorithm negotiation, which is characterized by comprising:  The user equipment sends, to the network side, information about an algorithm that can be used by the user equipment to derive the key KASME;  Receiving information of the selected algorithm sent by the network side after the selection algorithm. [15] A user equipment, comprising:  The transceiver unit is configured to: send, to the network side device, information about an algorithm that can be used by the user equipment to derive the key KA SME, and receive information about the selected algorithm sent by the network side device after the selection algorithm.  [16] An algorithm negotiation system, capable of communicating with a user equipment, comprising: a home client server HSS and a mobility management entity MME, wherein:  The HSS is configured to obtain information about an algorithm that can be supported by the user equipment by using an authentication data request message sent by the MME, and according to information about an algorithm that the user equipment and the HSS can support for deriving the key KASME Selecting an algorithm, and transmitting information of the selected algorithm to the MME through an authentication data response message;  The MME is configured to obtain information about an algorithm for deriving the key KASME supported by the user equipment from an attach or location update request of the user equipment forwarded by the base station, and support the user equipment The information of the algorithm for deriving the key KASME is sent to the HSS; and after the HSS selection algorithm, the information of the selected algorithm is received, and the information of the selected algorithm is sent to the user equipment by the base station.