CN100372431C

CN100372431C - End-to-end encipher communication method of CDMA system

Info

Publication number: CN100372431C
Application number: CNB2004100708026A
Authority: CN
Inventors: 郭平; 郄臣; 邹锋哨; 吴勇峰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2004-07-20
Filing date: 2004-07-20
Publication date: 2008-02-27
Anticipated expiration: 2024-07-20
Also published as: CN1725896A

Abstract

The present invention discloses an end-to-end encrypting communication method of a CDMA system, which is suitable to be used in a system including a KC and an OTAF. HLR/AC does not share SSD set by a user. The method comprises the following steps: a, a calling MS initiates encrypting calling identified by a called MS user to the HLR/AC; b, the HLR/AC obtains a service channel used for loading and bearing an OTAPA service to the calling MS, after the rights of the calling MS are successfully judged, conversation keys produced by the KC are sent to the calling MS through an OTAPA service; c, the HLR/AC obtains a service channel used for loading and bearing the OTAPA to the called MS, after the rights of the called MS are successfully judged, obtained conversation keys are sent to the called MS through the OTAPA service; d, the calling MS and the called MS utilize the obtained conversation keys to encrypt and decrypt call data. The method can realize the end-to-end encrypting communication of mobile users in the CDMA system.

Description

A kind of cdma system end to end security means of communication

Technical field

The present invention relates to the encryption communication technology, particularly relate to a kind of cdma system end to end security means of communication.

Background technology

Along with the widespread usage of mobile communication technology, fail safe has proposed more and more higher requirement to the user to mobile communication, particularly in some special industries, needs mobile communication that higher security performance is arranged.In existing code division multiple access (CDMA) network, operator provides the voice encryption business in order to improve fail safe.The voice encryption business only part of the wireless transmission between portable terminal and base station is carried out encryption to speech data, belongs to air interface voice ciphering.Therefore, existing cdma network is not accomplished end-to-end encryption communication, can not stop the possibility that voice are eavesdropped in the network transmission process of land with clear-text way.

In order to realize the End to End Encryption communication in the mobile communications network, the applicant has proposed a kind of End to End Encryption communication system in another patent application.For cdma system, the composition structure of this port-to-port encryption communication system mainly comprises as shown in Figure 1: portable terminal (MS), wireless access network equipment (BTS/BSC), core network side apparatus, cipher key center (KC).

Wherein, the core network side apparatus comprises all functional entitys in the existing cdma system core network, the mobile switching centre/Visited Location Registor (MSC/VLR) that only draws, attaching position register/AUC (HLR/AC) and over the air, OTA function (OTAF) entity here.The core network side apparatus is used to realize that the key information between MS and the KC is mutual; Also the call proceeding of MS is controlled.Employed key information when KC is used for generation and distribution MS communication.KC is positioned at the core network side that links to each other with wireless access network, and KC can be arranged in the consolidated network entity with HLR/AC and OTAF.MS obtains the required key information of communication by wireless access network and core network from KC, and uses the key information encryption/decryption services data that obtain.

Though the applicant has proposed a kind of End to End Encryption communication system,, for how in existing cdma network, the speech data in the end-to-end communication to be carried out encryption concrete implementation is not proposed also.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of cdma system end to end security means of communication, realizes the encryption communication end to end of mobile subscriber in the cdma system.

For achieving the above object, technical scheme of the present invention is achieved in that

The invention discloses a kind of cdma system end to end security means of communication, be applicable to the system that comprises cipher key center (KC) and over the air, OTA function (OTAF); HLR/AC is provided with public enciphered data (SSD) to the user and does not share, and this method may further comprise the steps:

A. caller MS initiates to comprise the call encryption of called MS user ID to HLR/AC;

B.HLR/AC utilizes the unique challenge flow process to obtain to be used to carry the professional Traffic Channel to caller MS of aerial parameter management (OTAPA), and described unique challenge flow process is the authentication process that HLR/AC starts; HLR/AC is distributed to caller MS by the OTAPA business with the session key that is used for this conversation that KC produces to after the caller MS authentication success;

C.HLR/AC utilizes the unique challenge flow process to obtain to be used to carry the Traffic Channel to called MS of OTAPA business, and described unique challenge flow process is the authentication process that HLR/AC starts; HLR/AC will be distributed to called MS to after the called MS authentication success from the session key that is used for this conversation that KC obtains by the OTAPA business;

D. the session key of caller MS and called MS utilization acquisition carries out encryption and decryption to communicating data.

The authentication process that described HLR/AC starts comprises: HLR/AC sends to MSC the authentication of MS is indicated, and MSC returns authentication indication response after receiving the authentication indication; MSC and MS carry out unique challenge reciprocal process; MSC sends the authentication status report to HLR/AC, and HLR/AC returns authentication status report response after receiving the authentication status report.

In the such scheme, if called MS belongs to different HLR/AC with caller MS, then step c also comprises: the HLR/AC of called MS ownership to the success of called MS authentication after, be initiated to the session key request of the HLR/AC of caller MS ownership, after the HLR/AC of caller MS ownership receives the session key request, return the session key request response of carrying this conversation session key to the HLR/AC of called MS ownership, carry out described session key then and be distributed to called MS acquisition.

In addition, if the user inserts encryption communication first, then this method further comprises: HLR/AC to the success of caller MS or called MS authentication after, HLR/AC initiates the OTAPA business to caller MS or called MS and carries out the mutual of encryption key, to obtain encryption key and to be distributed to MS.Correspondingly, among step b or the c, described HLR/AC further comprises the process that session key is distributed to MS: HLR/AC encrypts the session key that will be distributed to MS; Accordingly, MS is decrypted the encryption session key of receiving, obtains described session key.

In the such scheme, steps d may further include: described communicating data transmits by no vocoder serial operation TFO mode.

If the calling subscriber is the cdma system mobile subscriber, the called subscriber is a fixed-line subscriber, and then this method is except comprising described step a, b, and this method is further comprising the steps of:

C ' .HLR/AC is to the GMSC point-to-point transmission SMDPP message that sends SMS message, and sends the session key of this conversation to GMSC;

D '. utilize the session key that obtains that speech data is carried out encryption and decryption between caller MS and the GMSC.

Wherein, described steps d ' further comprise: GMSC sends the called subscriber to after the voice of caller MS are decrypted, and sends caller MS to after called subscriber's voice are encrypted.

In addition, this method may further include: HLR/AC, KC and OTAF are arranged in the consolidated network entity, or KC and OTAF are arranged among the HLR/AC.

By such scheme as can be seen, key of the present invention is: utilize the unique challenge flow process to obtain to be used to carry the Traffic Channel of OTAPA business, and finish the distribution of the session key that is used for this conversation by the OTAPA business, the two ends of communication utilize the session key that obtains to carry out speech scrambling.

Therefore, this cdma system end to end security means of communication provided by the present invention, not only can realize the end-to-end speech scrambling between the mobile subscriber in the cdma system, can also realize the speech scrambling of mobile subscriber and fixed-line subscriber or its network termination in the cdma system.And, cipher key center in the inventive method and OTAF can place in the HLR/AC entity, or cipher key center, OTAF and HLR/AC placed the consolidated network entity, bear by HLR/AC or this network entity that subscription authentication and key produce, the work of distribution, save unnecessary signaling interaction between HLR/AC and cipher key center and the OTAF.

Description of drawings

Fig. 1 is the composition structural representation of CDMA end to end security communication system;

Fig. 2 is the realization flow figure that caller MS of the present invention, called MS belong to the end to end security means of communication of same HLR/AC;

Fig. 3 is the realization flow figure that caller MS of the present invention, called MS belong to the end to end security means of communication of different HLR/AC;

Fig. 4 is the realization flow figure of mobile subscriber of the present invention to the end to end security means of communication of the portable terminal of fixed terminal or its net.

Embodiment

The present invention is further described in more detail below in conjunction with drawings and the specific embodiments.

Key of the present invention is to utilize the unique challenge flow process to obtain to be used to carry the Traffic Channel of OTAPA business, and finishes the distribution of the session key that is used for this conversation by the OTAPA business, and the two ends of communication utilize the session key that obtains to carry out speech scrambling.

Aerial parameter management (OTAPA, Over The Air Parameter Administration) business is the operation that a kind of network side initiatively manages the data in the portable terminal, can inquire about, revises or add the data in the portable terminal.Such as: network side can be by the professional KI (A_Key) that initiatively upgrades in the portable terminal of OTAPA.Among the present invention, HLR/AC initiates the OTAPA business by OTAF to portable terminal, this portable terminal is carried out this needed key information of conversing write on this portable terminal.

Usually, the OTAPA service needed is in the user under the condition of stable state and carries out.User's stable state is meant that the user is in idle condition or has stable Traffic Channel.Therefore, in order in the call encryption process, to finish the distribution of the key information that is used to converse, need set up stable Traffic Channel and carry the OTAPA business by the OTAPA business.The present invention obtains stable Traffic Channel by the unique challenge flow process.Before carrying out unique challenge, the request of can be earlier initiating authorizing procedure by MSC is to HLR/AC, and then by HLR/AC startup unique challenge flow process.

In cdma system, authentication is divided into public enciphered data (SSD) and shares or not two kinds of forms with SSD, SSD shares and is meant that the AC of AUC passes to VLR with the authorization data and the algorithm of travelling carriage, and authentication can be carried out in VLR or MSC, needn't all go AC to carry out authentication at every turn.SSD does not share and is meant that all authorization datas and algorithm only are kept among the AC, and each authentication all must be finished through AC.Among the present invention, HLR/AC is provided with SSD to the user and does not share, and like this, all must arrive among the HLR/AC subscription authentication at every turn and carry out.Wherein, HLR/AC can also can be the HLR that comprises the AC function for comprising the network entity of HLR and AC.

For the situation that SSD does not share, the unique challenge flow process is the authentication process that is started by HLR/AC.Receive that at MSC when initiating the request of unique challenge flow process by HLR/AC, MSC can set up a stable Traffic Channel for the unique challenge flow process, this Traffic Channel can be used for OTAPA is professional.When carrying out unique challenge, HLR/AC produces random number and authenticating result, and gives MSC/VLR with the random number and the authenticating result that are produced, and MSC/VLR sends to portable terminal with random number by the authentication query messages on the Traffic Channel.Portable terminal is according to the random number compute authentication result who receives, and the authenticating result that calculates is returned to MSC/VLR by the authentication query response message, MSC/VLR compares the authenticating result of self with the authenticating result of receiving, to confirm whether authentication is successful, if authentication success, then send the authentication status report of authentication success, otherwise send the authentication status report of failed authentication.Like this, both finished user's legitimacy authentication, also can provide stable Traffic Channel for the OTAPA business by authentication and unique challenge flow process.

In the some embodiments of the present invention, KC and OTAF module can be arranged in the HLR/AC entity, perhaps KC, OTAF and HLR/AC are placed the consolidated network entity, bear the generation and the distribution of subscription authentication and key information by HLR/AC or this network entity, can save unnecessary signaling interaction between HLR/AC and KC and the OTAF like this.Otherwise, if KC, OTAF module are separately positioned in the different physical entities with HLR/AC, HLR/AC need obtain the key information that is produced by KC by Signalling exchange in KC, HLR/AC carries out Signalling exchange to require OTAF module initiation OTAPA business with the OTAF module more then.

Based on cdma system end to end security communication system shown in Figure 1, if called MS and caller MS belong to same HLR/AC, the method that the present invention realizes the end to end security communication as shown in Figure 2.Wherein, caller MS belongs to OMSC, called MS ownership VMSC.In the present embodiment, KC and OTAF module are arranged in the HLR/AC entity.

Suppose the coded communication business that caller MS and called MS have all been contracted end-to-end, as shown in Figure 1, the present invention realizes that the method for end to end security communication may further comprise the steps:

Step 201～202, caller MS initiate to comprise the call encryption of called MS Subscriber Number, and OMSC initiates authentication request AUTHREQ to HLR/AC.Wherein, carry the mobile station identification number (MIN) of caller MS and the travelling carriage number (MDN) of called MS in the authentication request.Beginning is exhaled trigger if HLR/AC has contracted, and then caller MS can directly call and ask HLR/AC.

After step 203, HLR/AC received the authentication request AUTHREQ of the MIN that comprises caller MS, HLR/AC found the caller MS end to end security communication traffic of having contracted, and HLR/AC initiates the unique challenge flow process.

Wherein, the unique challenge flow process comprises:

Authentication Indication message AUTHDIR to caller MS is sent to OMSC in step 2031～2032, HLR/AC, comprises authentication parameters such as random number and authenticating result among the authentication Indication message AUTHDIR; After OMSC receives authentication Indication message AUTHDIR, return authentication indication response authdir to HLR/AC.

Step 2033, OMSC and caller MS finish unique challenge reciprocal process.Wherein, unique challenge reciprocal process is exactly the authentication process of MSC to MS.Exactly concrete: MSC will be handed down to MS from the random number the authentication parameter that HLR/AC obtains; MS is according to the random number compute authentication result that receives, and the authenticating result that calculates is returned to MSC; After MSC receives authenticating result, authenticating result of receiving and the authenticating result that is stored among the VLR are compared, whether successful to confirm authentication.

Whether successful step 2034～2035, OMSC send authentication status report ASREPORT to HLR/AC, comprise authentication information among the authentication status report ASREPORT; After HLR/AC receives authentication status report ASREPORT, return authentication status report response asreport to OMSC.

The purpose of carrying out unique challenge is to obtain to be used to carry the Traffic Channel of OTAPA business, finishes the authentication to caller MS simultaneously.

Step 204, after finishing the unique challenge flow process, whether successful HLR/AC returns authentication request response authreq to OMSC, carry authentication information; If the authentication success then continues execution in step 205, otherwise process ends.

Step 205, HLR/AC to the success of caller MS authentication after, if the user inserts encryption communication first, then HLR/AC initiates the reciprocal process that the OTAPA business is carried out encryption key, is used to obtain encryption key, and gives caller MS with the encryption key distribution that obtains; Otherwise this converses HLP/AC according to user's configuration determination whether needs are changed encryption key, change encryption key if desired, then HLR/AC initiates the reciprocal process that the OTAPA business is carried out encryption key to caller MS, execution in step 206 then, if do not need to change encryption key, then direct execution in step 206.

Step 206, HLR/AC generate session key, and use the encryption key that obtains that session key is encrypted, and HLR/AC initiates the OTAPA business to caller MS, send the session key after encrypting to caller MS.

Wherein, session key is the key that is used for communicating data is carried out encryption and decryption in this communication process, and encryption key is the key that session key is carried out encryption and decryption.

After step 207～210, OMSC receive the authentication request response authreq that comprises the authentication successful information that HLR/AC sends, the position requests LOCREQ that initiates called MS to HLR/AC; After HLR/AC receives position requests LOCREQ, initiate route requests ROUTREQ to the VMSC/VLR of called MS ownership; After the VMSC/VLR of called MS ownership receives route requests ROUTREQ, return the route requests response routreq of the mobile station roaming number that comprises called MS to HLR/AC; After HLR/AC receives route requests response routreq, return the position request response locreq of the VMSC routing iinformation that comprises the called MS ownership to OMSC.

Wherein, OMSC can carry out with step 205 synchronously to the step 207 that HLR/AC initiates the position requests LOCREQ of called MS.

After step 211～212, OMSC receive position request response locreq, be initiated to the replay call of VMSC, VMSC receives paging called MS behind the replay call.

Step 213～214, VMSC initiate authentication request AUTHREQ to HLR/AC; After HLR/AC received the authentication request AUTHREQ of the MIN that comprises called MS, HLP/AC found the called MS end to end security communication traffic of having contracted, and HLR/AC initiates the unique challenge flow process.Wherein, the unique challenge flow process exhales part identical with the beginning.

After step 215, HLR/AC carry out unique challenge to called MS, if the user inserts encryption communication first, then HLR/AC initiates the reciprocal process that the OTAPA business is carried out encryption key to called MS, is used to obtain encryption key, and gives called MS with the encryption key distribution that obtains; Otherwise this converses HLR/AC according to user's configuration determination whether needs are changed encryption key, change encryption key if desired, then HLR/AC initiates the reciprocal process that the OTAPA business is carried out encryption key, execution in step 216 then, if do not need to change encryption key, then direct execution in step 216.

Step 216, HLR/AC are according to the user ID of caller MS and called MS or the conversation sign (BillingID) of chargeing, search the session key of this conversation, and use the encryption key that obtains that the session key that inquires is encrypted, HLR/AC initiates the OTAPA business to called MS, sends the session key after encrypting to called MS.

Step 217～218, HLR/AC return VMSC authentication request response authreq, and whether successful authentication request response authreq carry authentication information; If the authentication success, then VMSC returns the response that continues to OMSC, otherwise process ends.

Step 219～220, called MS ring; After called MS was replied, the session key that caller MS and called MS utilization obtain carried out encryption and decryption to speech data, realized speech scrambling.

Wherein, voice channel between caller MS and the called MS is two-way a transparent Digital Transmission passage or a path, such as, can adopt the transparent channel of no vocoder serial operation (TFO, Tandem Free Operation) mode to transmit through the speech data of encrypting.Utilize the TFO formula, only need travelling carriage to carry out the coding/decoding of speech data, the vocoder of system does not participate in the processing of speech data and conversion.

As shown in Figure 3, called MS belongs to different HLR/AC with caller MS, and caller MS belongs to HLR1/AC1, and called MS belongs to HLR2/AC2.The present invention realizes the method for end to end security communication except comprising step 301～320 identical with step 201 shown in Figure 2～220, and after execution of step 3 14, this method is further comprising the steps of:

Step 314 '～315 ', the HLR2/AC2 of called MS ownership to the success of called MS authentication after, be initiated to the session key request message of the HLR1/AC1 of caller MS ownership, after the HLR1/AC1 of caller MS ownership receives the session key request message, HLR2/AC2 to the called MS ownership returns the session key request response, carries the required session key of this conversation in the response message.Continue execution in step 315 then.

In addition, user terminal among the present invention can also be fixing user terminal, fixed-line subscriber such as public switch telephone network (PSTN), or the mobile subscriber of its net, at this moment, end in the end to end security communication of the present invention is exactly gateway MSC (GMSC), then the present invention realize the end to end security communication method as shown in Figure 4, may further comprise the steps:

Step 401～406, with step 201～206th, similarly, its difference only is: if caller MS begins to call out, then called number is the mobile subscriber number that net a fixed-line subscriber number or its;

Step 407, HLR/AC judge that called number is non-Home Network Subscriber Number, directly to GMSC point-to-point transmission (SMDPP, the SMS Delivery Point To Point) message that sends SMS message, send session key to GMSC by SMDPP message.

Step 408, caller MSC are routed to GMSC according to called number.

After step 409, GMSC finish the work that continues of callee side, return the response that continues to the OMSC of caller MS ownership.

Step 410, called subscriber's ring; Behind the called subscriber answer, caller MS and GMSC use the session key that obtains that speech data is carried out encryption and decryption.GMSC is decrypted the voice of caller MS and sends the called subscriber to, called voice is encrypted sent to caller MS.That is to say that GMSC is to conversing with the plaintext form between the terminal called.

The present invention is applicable to that also the calling subscriber is the mobile subscriber of fixing user terminal or its net, the called subscriber is Home Network mobile subscriber's a situation, its encipher communication method and called subscriber are the mobile subscribers of fixing user terminal or its net, the called subscriber is similar for the Home Network mobile subscriber, its difference only is because the beginning exhales and exhale object different eventually, the execution sequence difference of method step, and GMSC needed to obtain the positional information of called MS before carrying out replay call.

By such scheme as seen, GMSC has served as the role who encrypts gateway, is transferred to the mobile subscriber again after being encrypted by its voice to fixed-line subscriber, sends fixed-line subscriber again to after mobile subscriber's voice are decrypted.

In a word, the above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. cdma system end to end security means of communication are applicable to the system that comprises cipher key center KC and over the air, OTA function OTAF; It is characterized in that HLR/AC is provided with public enciphered data SSD to the user and does not share, this method may further comprise the steps:

B.HLR/AC utilizes the unique challenge flow process to obtain to be used to carry the Traffic Channel to caller MS of aerial parameter management OTAPA business, and described unique challenge flow process is the authentication process that HLR/AC starts; HLR/AC is distributed to caller MS by the OTAPA business with the session key that is used for this conversation that KC produces to after the caller MS authentication success;

2. method according to claim 1 is characterized in that, the authentication process that described HLR/AC starts comprises:

HLR/AC sends to MSC the authentication of MS is indicated, and MSC returns authentication indication response after receiving the authentication indication; MSC and MS carry out unique challenge reciprocal process; MSC sends the authentication status report to HLR/AC, and HLR/AC returns authentication status report response after receiving the authentication status report.

3. method according to claim 1 is characterized in that, called MS belongs to different HLR/AC with caller MS, and then step c also comprises:

The HLR/AC of called MS ownership to the success of called MS authentication after, be initiated to the session key request of the HLR/AC of caller MS ownership, after the HLR/AC of caller MS ownership receives the session key request, return the session key request response of carrying this conversation session key to the HLR/AC of called MS ownership, carry out described session key then and be distributed to called MS acquisition.

4. according to claim 1 or 3 described methods, it is characterized in that, the user inserts encryption communication first, then this method further comprises: HLR/AC to the success of caller MS or called MS authentication after, HLR/AC carries out the mutual of encryption key to caller MS or called MS initiation OTAPA business, to obtain encryption key and to be distributed to MS.

5. according to claim 1 or 3 described methods, it is characterized in that among step b or the c, described HLR/AC further comprises the process that session key is distributed to MS: HLR/AC encrypts the session key that will be distributed to MS; Accordingly, MS is decrypted the encryption session key of receiving, obtains described session key.

6. according to claim 1 or 3 described methods, it is characterized in that steps d further comprises: described communicating data transmits by no vocoder serial operation TFO mode.

7. according to claim 1 or 3 described methods, it is characterized in that the calling subscriber is the cdma system mobile subscriber, the called subscriber is a fixed-line subscriber, and then this method is except comprising described step a, b, and this method is further comprising the steps of:

8. method according to claim 7 is characterized in that, described steps d ' further comprise: GMSC sends the called subscriber to after the voice of caller MS are decrypted, and sends caller MS to after called subscriber's voice are encrypted.

9. according to claim 1 or 3 described methods, it is characterized in that this method further comprises: HLR/AC, KC and OTAF are arranged in the consolidated network entity, or KC and OTAF are arranged among the HLR/AC.