CN101227272A

CN101227272A - System and method for obtaining media stream protection cryptographic key

Info

Publication number: CN101227272A
Application number: CN 200710000760
Authority: CN
Inventors: 何承东; 严军; 张占军
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2007-01-19
Filing date: 2007-01-19
Publication date: 2008-07-23
Also published as: WO2008089694A1

Abstract

The invention provides a method and a system for obtaining media stream protecting secret keys, which in particular comprises: sending conversion request message to a network entity by calling terminal equipment (UE), adding the media stream protecting secret keys into the conversion request message by the network entity, sending to a called UE, returning response message to the network entity by the called UE, adding the media stream protecting secret keys into the response message by the network entity, and sending to the calling UE. The method can also comprise: obtaining secret keys from a key management function entity (KMF) after the network entity receives the conversion request message, respectively sending the key secrets which are obtained to the terminal equipment UE and a medium processing function entity (MP) by the network entity. The secret keys which are generated can be respectively sent to the terminal equipment UE and the medium processing function entity (MP) from a network side through applying the invention and thereby the purpose for protecting the media stream which is transmitted can be achieved.

Description

A kind of method and system that obtains media stream protection cryptographic key

Technical field

The present invention relates to the media stream privacy technology, particularly relate to a kind of method and system that obtains media stream protection cryptographic key.

Background technology

IP multimedia service subsystem (IMS, IP Multimedia Network Subsystem) is fixing and mobile network's core session control layer, it is one of emphasis of communications field development, and at third generation partnership projects (3GPP, The Third Generation Partnership Project) and the telecommunications of advanced networks and the internet service and the consensus standard tissue (TISPAN that merge, Telecommunicationsand Internet Converged Services and Protocols for Advanced Networking) defined the standard relevant in IMS, such as: the network architecture, interface, agreement or the like.

Wherein, safety problem is the importance that 3GPP and TISPAN formulate standard.In order to guarantee safety, the IMS network is divided into input field and network domains, and has defined the safety standard of input field and network domains respectively.

But at present about the standard of safety all at chain of command in the IMS network, promptly how to guarantee the safety of session protocol in the IMS network, Media Stream itself then is to pass through plaintext transmission.In this case, the user is in communication process, and Media Stream may be eavesdropped, alter etc., and user's communication safety can't be protected.

Summary of the invention

In view of this, the embodiment of the invention provides a kind of method and system that obtains media stream protection cryptographic key, and calling terminal equipment (UE) and called UE can be obtained key from network side, thereby can protect to the Media Stream of user's transmission the user.

The embodiment of the invention also provides a kind of method and system of media stream protection cryptographic key, and UE and medium processing capacity entity (MP) can obtain key from network side, thereby can protect the Media Stream of user-to-network transmission.

For first goal of the invention, the technical scheme that the present invention proposes is:

A kind of method of obtaining media stream protection cryptographic key, this method may further comprise the steps:

A, calling terminal equipment UE send conversation request message to network entity, and network entity adds media stream protection cryptographic key in the described conversation request message to, and send to called UE;

B, called UE are returned response message to network entity, and network entity adds media stream protection cryptographic key in the described response message to, and send to calling UE.

For second goal of the invention, the technical scheme that the present invention proposes is:

A kind of system that obtains media stream protection cryptographic key, this system comprises:

The calling terminal equipment UE is used for sending conversation request message to network entity, and receives the conversational response message that carries media stream protection cryptographic key;

Network entity is used to receive the conversation request message of sending from calling UE, media stream protection cryptographic key is added in the conversation request message, and send to called UE; Also be used to receive the conversational response message that called UE sends, just media stream protection cryptographic key adds in the conversational response message, and sends to calling UE;

Called UE is used to receive the conversation request message of sending from network entity, and returns conversational response message.

For the 3rd goal of the invention, the technical scheme that the present invention proposes is:

After A, network entity receive conversation message, from key management function entity KMF, obtain key;

B, network entity send to terminal equipment UE and medium processing capacity entity MP respectively with the key that obtains.

For the 4th goal of the invention, the technical scheme that the present invention proposes is:

Terminal equipment UE is used to receive the key that network entity sends;

Medium processing capacity MP is used to receive the key that network entity sends;

Network entity is used to receive conversation message, and obtains key from key management functions KMF, and sends to UE and MP;

Key management functions KMF is used to generate key.

In sum, the present invention proposes a kind of method and system that obtains media stream protection cryptographic key, can generate key by network side, and gives the entity of Media Stream that needs protection with the delivering key that generates, thereby reaches the purpose that the Media Stream of transmission is protected.In addition, because key is by network side entity or functional unit, promptly KMF generates key, can satisfy the actual demand of third party's Lawful Interception.

Description of drawings

Fig. 1 is the flow chart of the inventive method embodiment one;

Fig. 2 is the inventive method embodiment two message flow schematic diagrames;

Fig. 3 is the inventive method embodiment three message flow schematic diagrames;

Fig. 4 is that user of the present invention flows system's basic structure schematic diagram under the protection situation to user media;

Fig. 5 a is system embodiment one a basic structure schematic diagram of the present invention;

Fig. 5 b is system embodiment two basic structure schematic diagrames of the present invention;

Fig. 6 is the flow chart of the inventive method embodiment four;

Fig. 7 is the message flow schematic diagram of the inventive method embodiment five Calling Sides;

Fig. 8 is the message flow schematic diagram of the inventive method embodiment five callee sides;

Fig. 9 is the message flow schematic diagram of the inventive method embodiment six Calling Sides;

Figure 10 is the message flow schematic diagram of the inventive method embodiment six callee sides;

Figure 11 is the message flow schematic diagram of the inventive method embodiment seven Calling Sides;

Figure 12 is the message flow schematic diagram of the inventive method embodiment seven callee sides;

Figure 13 is the message flow schematic diagram of the inventive method embodiment eight Calling Sides;

Figure 14 is the message flow schematic diagram of the inventive method embodiment eight callee sides;

Figure 15 is system's basic structure schematic diagram under the user-to-network media stream protection situation of the present invention;

Figure 16 is system embodiment three basic structure schematic diagrames of the present invention;

Figure 17 is system embodiment four basic structure schematic diagrames of the present invention.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with the accompanying drawings and the specific embodiments.

Basic thought of the present invention is to obtain the key that generates by network side entity, delivering key is given the entity that need protect the Media Stream of transmission again.Described herely need can be terminal equipment (UE), also can be the medium processing capacity entity (MP) in the network the entity protected of Media Stream of transmission.That is to say that can obtain media stream protection cryptographic key by calling UE and called UE, after this Media Stream that transmits between calling UE and the called UE can utilize this key to protect, and promptly carries out the protection of user to the user; Also can obtain media stream protection cryptographic key by the UE and the MP of certain network side, after this Media Stream that transmits between UE and the MP also can utilize this key to protect, and promptly carries out the user-to-network protection.

The present invention is directed to the user to the protection of user media stream and the protection of user-to-network Media Stream, a kind of method and system that obtains media stream protection cryptographic key is provided respectively.

For the situation of protection user to the Media Stream of user's transmission, Fig. 1 is the flow chart that the method embodiment one of media stream protection cryptographic key is obtained in realization.As shown in Figure 1, method embodiment one can may further comprise the steps:

Step 101: the calling terminal equipment UE sends conversation request message to network entity, and network entity adds media stream protection cryptographic key in the described conversation request message to, and sends to called UE.

In the practical application, network entity comprises caller network entity and called network entity, and described step 101 can comprise:

After step a1, caller network entity are received the affirmation PRACK message that calling UE sends or are upgraded the UPDATE request message, obtain the key that this adnation becomes to caller key management function entity KMF, and described key is sent to the called network entity by PRACK or UPDATE request message.

Here, described caller network entity can be calling conversation control function entity S-CSCF or caller application server AS, so, described originating S-CSCF or caller AS to caller KMF obtain the key that this adnation becomes method can for:

Originating S-CSCF or caller AS send secret key request message to caller KMF, and caller KMF returns to originating S-CSCF or caller AS with the key that generates by key response message.

After step a2, called network entity are received PRACK or UPDATE request message; obtain the key that this adnation becomes to called key management function entity KMF; determine media stream protection cryptographic key according to the key of this adnation one-tenth and the key of Calling Side generation again, and media stream protection cryptographic key is sent to called UE by PRACK or UPDATE request message.

Correspondingly, called network entity described here can be terminating S-CSCF or called AS, so, described terminating S-CSCF or called AS to called KMF obtain the key that this adnation becomes method can for: terminating S-CSCF or called AS send secret key request message to called KMF, and called KMF returns to terminating S-CSCF or called AS with the key that generates by key response message.

In addition, called network entity described here has obtained the key that key that Calling Side generates becomes with this adnation, and the key that can be directly the key of described Calling Side generation be become with this adnation is as media stream protection cryptographic key; Afterwards, after described called UE receives described conversation request message, the key that the cipher key derivative that the key that called UE generates according to the Calling Side in the described conversation request message becomes with this adnation makes new advances, and with the key that derives as media stream protection cryptographic key.

In the practical application, the called network entity, i.e. the key that makes new advances of terminating S-CSCF or the called AS cipher key derivative that can also become with this adnation according to the key that Calling Side generates, and with the key that derives as media stream protection cryptographic key.

Step 102: called UE is returned response message to network entity, and network entity adds media stream protection cryptographic key in the described response message to, and sends to calling UE.

Step 102 described here can comprise:

After step b1, called network entity were received 200 response messages that called UE returns, the key that this side is generated in advance was carried in described 200 response messages, and sends to the caller network entity;

After step b2, caller network entity were received described 200 response messages, the key that key that generates in advance according to this side and callee side generate was determined media stream protection cryptographic key, and media stream protection cryptographic key added in described 200 response messages sent to calling UE.

Caller network entity described here is originating S-CSCF or caller AS; the key that key that originating S-CSCF or caller AS can directly become this adnation and callee side generate is as media stream protection cryptographic key; and after described calling UE receives conversational response; the key that the cipher key derivative that key that is become according to this adnation in the conversational response message by calling UE and callee side generate makes new advances, and with the key that derives as media stream protection cryptographic key.

In the practical application, the key that the cipher key derivative that key that originating S-CSCF or caller AS can also become according to this adnation and callee side generate makes new advances, and with the key that derives as media stream protection cryptographic key.

In the practical application, before calling UE and called UE are obtained media stream protection cryptographic key, can also hold consultation to security capabilities, its method can for:

The session that the media flow security ability information that self provides will be provided calling UE is set up request message and is sent to called UE by network entity, and described session is set up request message for inviting (INVITE) request message; The media flow security ability information that called UE provides according to calling UE is provided by the media flow security ability information that self need provide, and the media flow security ability information that provides is carried on session sets up in the response response message, return to calling UE by network entity, it is 183 response messages that response message is set up in described session.

In the process of consulting, when the caller network entity receives described INVITE request message, this method further comprises: the caller network entity is judged the signatory media flow security business of calling UE, the sign of the signatory media flow security business of calling UE is added in the described INVITE request message, send to the called network entity again;

When the called network entity receives described INVITE request message, this method further comprises: the called network entity is checked out the calling UE sign of signatory media flow security business in the described request message, judge the also signatory media flow security business of called UE again, continue again to carry out;

When the called network entity receives described 183 response messages, this method further comprises: the called network entity adds the sign of the signatory media flow security business of called UE in described 183 response messages to, more described 183 response messages is sent to the caller network entity;

When the caller network entity received described 183 response messages, this method further comprised: the caller network entity is checked the called UE sign of signatory media flow security business in the outbound message, continues to carry out again.

For the scheme of obtaining key that proposes to user media stream protection situation at the user is described better, be described in detail with preferred approach embodiment and system embodiment below.

Method embodiment two

In the present embodiment, the network entity that obtains Calling Side generation key is caller AS, and the entity of generation key is caller KMF, is an independent entity; The network entity that obtains callee side generation key is called AS, and the entity that generates key is called KMF, is an independent entity.

In the present embodiment, suppose all signatory media stream protection business of calling UE and called UE.

Fig. 2 is the message flow schematic diagram of method embodiment two.As shown in Figure 2, the method that calling UE and called UE are obtained media stream protection cryptographic key among the method embodiment two can may further comprise the steps:

Step 201: calling UE sends session to caller CSCF and sets up request message, and described session is set up request message and carried the media flow security ability information that calling UE provides.

It is invitation (INVITE) message in the Session Initiation Protocol that request message is set up in the described session of this step; described media flow security ability information comprises security algorithm, can also comprise that one or more make up arbitrarily in medium type, secure transfer protocol type and the safe prerequisite that needs protection.

Security algorithm described here can be integrality security algorithm or confidentiality security algorithm, and the described medium type of protection that needs can be text, audio frequency, video etc., and described secure transfer protocol type can be RTP/SAVP or RTP/SAVPF etc.

Described safe prerequisite is to be used to refer to the requirement of this session to media flow security, can comprise the intensity sign of the media flow security protection of initiating the entity expectation, such as: compulsory (mandatory), optional (optional), insignificant (none).Described safe prerequisite can also comprise the security negotiation configuration result of expectation and current configuring condition, such as: whether finish negotiation, receive direction and finished security configuration, reception and sending method and all finish security configuration etc.

In addition, the media flow security ability information of calling UE described here can offer the media flow security ability information of called UE for calling UE.Such as: calling UE can be supported 5 kinds of security algorithms, and 3 kinds of security algorithms offer called UE but can only select wherein, so, 3 kinds of security algorithms that provided just can only be provided in the INVITE get final product.Certainly, calling UE also can with support 5 in security algorithm all offer called UE, how to determine that the media flow security ability information that provides then need be determined by actual conditions.

Step 202: caller CSCF sets up request message with described session and sends to caller AS.

In this step, caller CSCF can adopt the initial filter criteria of prior setting, request message is set up in session triggered to caller AS.Then belong to prior art as for how to trigger, repeat no more herein.

Step 203～step 205: caller AS judges the signatory media stream protection business of calling UE; add the sign of the signatory media stream protection business of calling UE to described session and set up in the request message, then session is set up request message and send to called CSCF by caller CSCF.

In the practical application, what described caller AS can be according to prior record judges the calling UE media stream protection business of whether having contracted with signatory relevant information.Such as: set up the described and signatory relevant information of sign inquiry of calling UE in the request message according to session, and judge calling UE according to described and signatory relevant information and whether contract.Certainly, caller AS also can adopt other method to check the signatory situation of calling UE, repeats no more herein.

Step 206: called CSCF receives after session sets up request message, request message is set up in described session sent to called AS.

Similar to Calling Side, called CSCF described here also can adopt the initial filter criteria of prior setting, request message is set up in session triggered to called AS.

Step 207～step 209: called AS checks out session is set up the signatory media stream protection business of calling UE in the request message sign; and judge the also signatory media stream protection business of called UE, then request message is set up in described session and sent to called UE by called CSCF.

Called AS described here also can adopt the method identical with Calling Side to judge the called UE media stream protection business of having contracted, and repeats no more herein.

Step 210～step 211: called UE sends session to called CSCF and sets up response response message, and called CSCF sets up response message with the session that receives again and sends to called AS.

Here, called UE can be set up calling UE provides in the request message media flow security ability information according to session the media flow security ability information that self need provide is provided, and will determine that the media flow security ability information that provides is carried on session and sets up in the response message, send to called AS by called CSCF.

It is 183 message that response message is set up in described session, and the media flow security ability information that described called UE need provide can be all or part of information that can be supported by calling UE.Such as: called UE definite calling UE from the INVITE that receives can be supported 3 kinds of security algorithms, if called UE self is only supported two kinds of security algorithms wherein, then can return the whole two kinds of security algorithms that to support, also can return wherein a kind of security algorithm to calling UE to calling UE.

Step 212～step 215: the called AS sign that called UE is signatory is added session to and is set up in the response message, and by called CSCF and caller CSCF response message is set up in session and sent to caller AS.

Step 216～step 218: caller AS checks out that session is set up and comprises the signatory sign of called UE in the response message, and response message is set up in described session sent to calling UE by caller CSCF.

In the present embodiment, step 201～step 218 is actually the process of between calling UE and the called UE security capabilities being held consultation, obtain the other side and can support parameters such as security algorithm, secure transfer protocol, thereby be identified for the media flow security ability information of this session.

In the process of calling UE and called UE negotiation, at Calling Side, caller AS needs also to check whether calling UE is signatory, and the sign that calling UE is signatory is added in the message; At callee side, called AS needs also to check whether called UE is signatory, and the sign that called UE is signatory is added in the response message that returns.In the practical application, if calling UE and called UE are the users of signatory media stream protection business of acquiescence, the media stream protection business is a basic business in other words, and all users do not need the inspection of contracting.In this case, caller AS and called AS also can not check signatory situation; Perhaps, caller AS and called AS also can a side check, and the opposing party does not check; Perhaps directly check signatory by caller CSCF and called CSCF.As for whether check signatory situation actually, all check by side inspection or both sides, check or check and can determine by CSCF according to actual conditions by AS, repeat no more herein.

Similar with the signatory situation of inspection, in the process of calling UE and called UE negotiation, if calling UE is signatory, caller AS also needs to add the sign that calling UE has been contracted to session and sets up in the request message; If called UE is signatory, called AS also needs to add the sign that called UE has been contracted to session and sets up in the response message.Like this, the signatory situation that Calling Side and callee side just can clear and definite the other side, thus can according to circumstances adopt different strategies.But in the practical application, caller AS and called AS also can that this side is not signatory advisory give the other side, so also add in the message with regard to need not the sign that this side UE is signatory.

Step 219～step 220: calling UE sends to caller AS by caller CSCF with the session request message.

Conversation request message described here can be affirmation (PRACK) message, and carries the media flow security ability information that is used for current sessions that calling UE is determined.

In this step, described calling UE be identified for current sessions the media flow security ability information method can for: the media safety ability information that calling UE provides according to called UE is identified for the media flow security ability information of current sessions.That is to say; calling UE can be selected the media flow security ability information that is used for this session from the media flow security ability information that called UE provides; comprise: security algorithm can also comprise that one or more make up arbitrarily in the medium type that needs protection, the secure transfer protocol type.

Step 221: caller AS obtains key K 1 from caller KMF.

In this step, when caller AS need obtain key K 1 from caller KMF, described caller AS can send secret key request message to caller KMF, and caller KMF generates key, again the key K 1 that generates is returned to caller AS.In addition, caller KMF can also will return to caller AS in the lump at information such as the key identification of key K 1, the key terms of validity.

Here, when caller AS sends secret key request message to caller KMF, the information such as security algorithm that are identified in the session request message in the media flow security ability information of this session can also be sent to caller KMF, described caller KMF can generate key according to information such as described security algorithms.In the practical application, caller KMF can not generate key according to information such as security algorithms in the described caller AS conversation request message yet, but directly generates key.No matter which kind of method of employing is as long as caller AS obtains key from caller KMF.

Step 222～step 225: caller AS adds the key K 1 that this adnation becomes in the conversation request message to, and sends to called AS by caller CSCF and called CSCF.

Step 226: called AS obtains key K 2 from called KMF.

Similar to step 221, called AS can send secret key request message to called KMF, and called KMF generates key, and the key K 2 that generates is returned to called AS.In addition, called KMF can also will return to called AS in the lump at information such as the key identification of key K 2, the key terms of validity.

Step 227～step 229: the key that the key K 2 that the key K 1 that called AS generates according to Calling Side becomes with this adnation is derived and made new advances; the key that derives as media stream protection cryptographic key, and is added to media stream protection cryptographic key in the described conversation request message and to send to called UE by called CSCF.

Step 230～step 231: called UE sends to called AS by called CSCF with the session response message.

Conversational response message described here is 200 message, can carry the media flow security ability information that called UE is confirmed.Described media flow security ability comprises security algorithm, can also comprise that one or more make up arbitrarily in medium type, secure transfer protocol type and the safe prerequisite that needs protection.

Step 232～step 235: called AS adds key K 2 in the described conversational response message to, and sends to caller AS by called CSCF and caller CSCF.

Here, if called KMF also will return to called AS at information such as the key identification of key K 2, the key terms of validity in advance in the lump, called AS just can also also add information such as described key identification at key K 2, the key term of validity in the described conversational response message.

Step 236～step 238: the key that the key K 2 that key K 1 that caller AS becomes according to this adnation and callee side generate is derived and made new advances; with the key that derives as media stream protection cryptographic key; and described media stream protection cryptographic key added in the conversational response message, send to calling UE by caller CSCF then.

In the present embodiment, Calling Side and callee side all generate key respectively, and the key that makes new advances of the cipher key derivative that generates of the key that becomes according to this adnation and the other side, and the key that derives is sent to calling UE and called UE respectively as media stream protection cryptographic key.After this, calling UE and called UE just can be utilized the Media Stream of described cryptographic key protection transmission.Need be when the called UE media stream such as: calling UE, be transferred to called UE after can utilizing the key that derives with media stream protection; On the contrary, if called UE need be to the calling UE media stream, be transferred to calling UE after also can utilizing the key that derives with media stream protection.

In the practical application, caller AS and called AS also can not generate derivative key, and the key that the key that directly this adnation is become and the other side generate is as media stream protection cryptographic key.That is to say that calling UE and called UE will obtain key K 1 and key K 2 simultaneously, the key of protection Media Stream when one of them key conduct sends to the other side, the another one key then is used to receive protected Media Stream.

Present embodiment is derived to key by caller AS and called AS, in the practical application, can also be derived to key by caller CSCF and called CSCF respectively; Perhaps, by calling UE and called UE key is derived respectively.

The method of the derivative key in the present embodiment can for: key K 1 is carried out character string with key K 2 and is connected, and also can enumerate no longer one by one here with key K 1 and key K 2 as the methods such as input parameter of key generating function.

In addition, KMF described in the present embodiment is an independent entity, and in the practical application, KMF also can be a functional unit in AS, CSCF or the home subscriber server entities such as (HSS).But no matter be independent entity, or a functional unit in certain entity, its method is similar to present embodiment with flow process, enumerates no longer one by one herein.

Method embodiment three

In the present embodiment, the network entity that obtains Calling Side generation key is caller CSCF, and the caller KMF that generates key is a functional unit among the caller AS; The network entity that obtains callee side generation key is called CSCF, and the called KMF that generates key is a functional unit among the called AS.

In addition, in the present embodiment, suppose calling UE and the called UE media stream protection business of all having contracted.

Fig. 3 is the message flow schematic diagram of present embodiment.As shown in Figure 3, present embodiment can may further comprise the steps:

Step 301: calling UE sends session to caller CSCF and sets up request message, and described session is set up request message and carried the media flow security ability information that calling UE provides.

This step is identical with the step 201 of implementing two, repeats no more herein.

Step 302: caller CSCF sets up request message with described session and sends to caller AS.

Step 303～step 305: caller AS judges the signatory media stream protection business of calling UE, then request message is set up in described session and is sent to called CSCF by caller CSCF.

This step is similar to step 203～step 205 of implementing two, and just that calling UE is the signatory sign of caller AS is added session to and set up in the request message, repeats no more herein.

Step 306: called CSCF receives after session sets up request message, again request message is set up in described session and is sent to called AS.

This step is identical with the step 206 of implementing two, repeats no more herein.

Step 307～step 309: called AS judges the also signatory media stream protection business of called UE, again request message is set up in described session and is sent to called UE by called CSCF.

This step is similar to step 207～step 209 of implementing two, is that called UE is the signatory sign of called AS is added session to and set up in the request message, repeats no more herein.

Step 310～step 312: called UE sends session to called CSCF and sets up response response message, and called CSCF sets up response response message with described session again and sends to calling UE by caller CSCF.

Here, called UE can be set up calling UE provides in the request message media flow security ability information according to session the media flow security ability information that self need provide is provided, and will determine that the media flow security ability information that provides is carried on session and sets up in the response message, send to calling UE by called CSCF and caller CSCF.

It is 183 message that response message is set up in session described here, and the media flow security ability information that described called UE need provide can be all or part of information that can be supported by calling UE.

In the present embodiment, step 301～step 312 is the processes of between calling UE and the called UE security capabilities being held consultation, and obtains the other side and can support parameters such as security algorithm, secure transfer protocol, thereby be identified for the media flow security ability information of this session.

Similar to embodiment two, in the practical application, in the process of consulting, caller AS and called AS also can not check signatory situation; Perhaps caller AS and called AS can a side check, and the opposing party does not check; Perhaps directly check signatory by caller CSCF and called CSCF.As for whether checking signatory situation actually, check or both sides check by a side, check or check that by AS wait can be definite according to actual conditions by CSCF, repeat no more herein.

In addition; similar to embodiment two; caller AS can also add the sign of the signatory media stream protection business of calling UE to session and set up in the request message, called AS can with called UE the sign of signatory media stream protection business add session to and set up in the response message.

Step 313: calling UE sends to caller CSCF with the session request message.

Step 314: caller CSCF obtains key K 1 from caller KMF.

This step is similar to the step 221 among the embodiment two, and its difference is: present embodiment is directly to obtain key K 1 from caller KMF by caller CSCF, can also obtain information such as key identification at key K 1, the key term of validity, repeats no more herein.

Step 315～step 316: caller CSCF adds the key K 1 that this adnation becomes in the conversation request message to, and the conversation request message that will carry key K 1 sends to called CSCF.

Step 317: called CSCF obtains key K 2 from called KMF.

This step is similar to step 314, repeats no more herein.

Step 318～step 319: the key that the key K 2 that the key K 1 that called CSCF generates according to Calling Side becomes with this adnation is derived and made new advances; the key that derives as media stream protection cryptographic key, and is added to media stream protection cryptographic key in the described conversation request message and to send to called UE.

Step 320: called UE is returned conversational response message to called CSCF.

Similar to method embodiment two, conversational response message described here also can be 200 message, can carry the media flow security ability information that called UE is confirmed.Described media flow security ability comprises security algorithm, can also comprise that one or more make up arbitrarily in medium type, secure transfer protocol type and the safe prerequisite that needs protection.

Step 321～step 322: called CSCF adds key K 2 in the conversational response message to, and the conversational response message that will carry key K 2 sends to caller CSCF.

If called KMF also will return to called CSCF at information such as the key identification of key K 2, the key terms of validity in advance in the lump, called CSCF just can also also add information such as described key identification at key K 2, the key term of validity in the conversational response message.

Step 323～step 324: the key that the key K 2 that key K 1 that caller CSCF becomes according to this adnation and callee side generate is derived and made new advances; with the key that derives as media stream protection cryptographic key; and described media stream protection cryptographic key added in the conversational response message, send to calling UE then.

Similar to method embodiment two, caller CSCF and called CSCF also can not generate derivative key in the present embodiment, and the key that the key that directly this adnation is become and the other side generate is as media stream protection cryptographic key; Perhaps generate derivative key by calling UE and called UE.

At this moment, calling UE and called UE have all been obtained media stream protection cryptographic key, can utilize described key that the Media Stream of transmission is protected.

In addition, in the practical application, calling UE is in the INVITE that called UE sends, except the media flow security ability information that can comprise that calling UE provides, can also increase the media flow security pattern, described safe mode can arrive user model for the user, also can be the pattern of user-to-network.

In this case, calling UE sends to caller AS with described INVITE by caller P-CSCF, originating S-CSCF earlier; When caller AS receives this INVITE, after checking the signatory media stream protection business of calling UE, if can also check this media flow security pattern media flow security pattern the option more than is arranged, then determine unique a kind of media flow security pattern, and the pattern in the modification message is this media flow security pattern of determining, continue again to carry out, that is: INVITE is sent to terminating S-CSCF; Terminating S-CSCF sends to called UE by called AS, called P-CSCF with described INVITE again; Called UE sends 183 message that the media flow security ability information that self provides is provided to called P-CSCF, and called P-CSCF sends to terminating S-CSCF again, and sends to called AS by terminating S-CSCF; Called AS sends to terminating S-CSCF with described 183 message after adding the media flow security pattern of determining; Terminating S-CSCF sends to originating S-CSCF again; Originating S-CSCF sends to caller AS after receiving described 183 message, and caller AS sends to originating S-CSCF with 183 message check the definite media flow security pattern of called network from described 183 message after; Originating S-CSCF sends to caller P-CSCF again; Caller P-CSCF confirms the media flow security pattern, and continues to send to calling UE, thereby finishes media flow security mode negotiation between calling UE and the called UE.

Obtain the method for media protection key at above-mentioned user UE under the user media stream protection situation, the present invention also proposes a kind of system that obtains media stream protection cryptographic key accordingly.

Fig. 4 is the basic structure schematic diagram of this system.As shown in Figure 4, this system comprises at least:

Calling terminal equipment UE 401 is used for sending conversation request message to network entity 402, and receives the conversational response message that carries media stream protection cryptographic key;

Network entity 402 is used to receive the conversation request message of sending from calling UE 401, media stream protection cryptographic key is added in the conversation request message, and send to called UE 403; Also be used to receive the conversational response message that called UE 403 sends, just media stream protection cryptographic key adds in the conversational response message, and sends to calling UE 401;

Called UE 403 is used to receive the conversation request message of sending from network entity 402, and returns conversational response message.

In the practical application, described network entity 402 comprises caller network entity and called network entity.Wherein,

Described caller network entity is used to receive the conversation request message that calling UE sends, and obtains key from caller key management functions KMF, and sends to the called network entity; Also be used to receive the conversational response message that called UE sends, the key that this side is generated in advance is carried in the response message, and sends to the caller network entity;

Described called network entity is used to receive the conversation request message from the caller network entity, obtains key from called KMF, determines media stream protection cryptographic key and by sending to called UE in the conversation request message; Also be used to receive the conversational response message that called UE is returned, the key that this adnation is become is carried on and sends to the caller network entity in the conversational response message.

In addition, Calling Side and callee side comprise a KMF respectively, i.e. caller KMF and called KMF.Wherein, described caller KMF is used to generate key and sends to the caller network entity; Described called KMF is used to generate key and sends to the called network entity.

In the practical application, described caller network entity can be calling conversation control function entity CSCF, also can be caller AS; Described called network entity can be called call conversation control function entity CSCF, also can be called AS.

KMF of the present invention can be an independent entity, also can be a functional unit among CSCF, AS or the HSS.CSCF described here can be S-CSCF, also can be P-CSCF.At CSCF is under the situation of S-CSCF, can also comprise P-CSCF in the system, is used to transmit the message between UE and the S-CSCF.

In order to illustrate that better above-mentioned user flows the system that obtains media stream protection cryptographic key under the protection situation to user media, is described in detail with preferable system embodiment below.

System embodiment one

Fig. 5 a is the basic structure schematic diagram of system embodiment one.Shown in Fig. 5 a, native system embodiment comprises: calling UE 401, network entity 402, called UE 403, caller KMF404, called KMF405, caller P-CSCF406, called P-CSCF407.

Wherein said network entity 402 comprises caller network entity and called network entity, and described caller network entity is an originating S-CSCF 4021, and described called network entity is a terminating S-CSCF 4022.

Described calling UE 401 is used for sending conversation request message by caller P-CSCF406 to originating S-CSCF 4021, and receives the conversational response message that carries media stream protection cryptographic key;

Described originating S-CSCF 4021 is used for receiving from caller P-CSCF406 conversation request message, and KMF405 obtains key from caller, and sends to terminating S-CSCF 4022; Also be used to receive reception conversational response message, the key that obtains be carried on send to calling UE 401 in the response message again from terminating S-CSCF 4022;

Described terminating S-CSCF 4022 is used to receive the conversation request message from originating S-CSCF 4021, obtains key from called KMF405, the key that obtains is carried in the conversation request message sends to called UE 403 by called P-CSCF407; Also be used to receive conversational response message, and be transmitted to originating S-CSCF 4021 from called UE 403;

Called UE 403 is used to receive conversation request message, and returns conversational response message;

Caller KMF404 is used to generate key, and returns to originating S-CSCF 4021;

Called KMF405 is used to generate key, and returns to terminating S-CSCF 4022;

Caller P-CSCF406 is used to transmit the message between calling UE 401 and the originating S-CSCF 4021;

Called P-CSCF407 is used to transmit the message between called UE 403 and the terminating S-CSCF 4022.

When needs obtained media stream protection cryptographic key, calling UE 401 sent conversation request message by caller P-CSCF4021 to originating S-CSCF 4021, and originating S-CSCF 4021 obtains key from caller KMF404, and sent terminating S-CSCF 4022; Terminating S-CSCF 4022 obtains key from called KMF405, send to called UE 403 by called P-CSCF407 again; Called UE 403 is returned conversational response message by called P-CSCF407 and is given terminating S-CSCF 4022, and terminating S-CSCF 4022 is carried on the key that obtains and sends to originating S-CSCF 4021 in the conversational response message; The conversational response message that originating S-CSCF 4021 will carry key again returns to calling UE 401 by caller P-CSCF406.

In the practical application, this system can also comprise caller AS and called AS, and originating S-CSCF 4021 obtains key by caller AS from caller KMF404, and terminating S-CSCF 4022 obtains key by called AS from called KMF405.

After obtaining key, called AS can also be further used for the key that the key that Calling Side generates becomes with this adnation is derived; Perhaps, terminating S-CSCF can also be further used for the key that the key that Calling Side generates becomes with this adnation is derived; Perhaps, called UE can also be further used for the key that the key that Calling Side generates becomes with this adnation is derived.

Correspondingly, obtain key after, caller AS can also be further used for the key that the key that callee side generates becomes with this adnation is derived; Perhaps, originating S-CSCF can also be further used for the key that the key that callee side generates becomes with this adnation is derived; Perhaps, calling UE can also be further used for the key that the key that callee side generates becomes with this adnation is derived.

In the practical application, caller AS and called AS can also be used for respectively to calling UE and the called UE media protection business of whether having contracted checking as for how to judge whether contract, can repeat no more referring to above-mentioned concrete method herein.

System embodiment two

Fig. 5 b is the basic structure schematic diagram of system embodiment two.Shown in Fig. 5 b, native system embodiment comprises: calling UE 401, network entity 402, called UE 403, caller KMF404, called KMF405, caller P-CSCF406, called P-CSCF407.

Wherein said network entity 402 comprises caller network entity and called network entity, and described caller network entity is caller AS 5021, and described called network entity is called AS 5022.

The function of each entity among the native system embodiment is similar to system embodiment one with structure, its difference is, the function of caller AS is equivalent to the originating S-CSCF in the system embodiment one among the native system embodiment, and the function of called AS is equivalent to the terminating S-CSCF in the system embodiment one.

Also can comprise originating S-CSCF 408 and terminating S-CSCF 409 simultaneously among the native system embodiment, just no longer possess function from key to KMF that obtain, only as transmitting message.

Certainly, identical with system embodiment one, obtain key after, called AS can also be further used for the key that the key that Calling Side generates becomes with this adnation is derived; Perhaps, terminating S-CSCF can also be further used for the key that the key that Calling Side generates becomes with this adnation is derived; Perhaps, called UE can also be further used for the key that the key that Calling Side generates becomes with this adnation is derived.

Caller AS and called AS can also be used for respectively to calling UE and the called UE media protection business of whether having contracted checking as for how to judge whether contract, can repeat no more referring to above-mentioned concrete method herein.

Use the scheme of said method embodiment and system embodiment, can generate key by network side, and send to calling UE and called UE respectively, calling UE and called UE just can utilize the key that obtains that the Media Stream of transmission is protected.In addition, because key is generated by network side, can satisfy the actual needs of third party's Lawful Interception.

Said method embodiment and system embodiment all are that promptly calling UE and called UE are obtained after the key at the example of user to the protection of user media stream, and the Media Stream that transmits between two UE can be omnidistance protected.But in actual applications; the Media Stream that transmits between two users also can not be omnidistance protected; and only protect wherein one section; promptly can protect the part of user-to-network; the network-to-network part then is a plaintext transmission; perhaps protect, repeat no more here by the security mechanism of network domains.

For the situation of the Media Stream of protecting the user-to-network transmission, Fig. 6 is the flow chart that the method embodiment of media protection key is obtained in realization, the i.e. flow chart of the inventive method embodiment four.

As shown in Figure 6, method embodiment four can may further comprise the steps:

Step 601: network entity obtains key after receiving conversation message from key management function entity KMF.

Step 602: network entity sends to terminal equipment UE and medium processing capacity entity (MP) respectively with the key that obtains.

Network entity described here can be S-CSCF, also can be AS.With the network entity is that S-CSCF is an example:

If at Calling Side, network entity described here can be originating S-CSCF, and described UE is a calling UE, and described MP is caller MP, and described KMF is caller KMF.Correspondingly, if at callee side, network entity described here can be terminating S-CSCF, and described UE is a called UE, and described MP is called MP, and described KMF is called KMF.That is to say, after originating S-CSCF receives conversation message, from caller KMF, obtain key, again the key that obtains is sent to calling UE and caller MP respectively.After terminating S-CSCF receives conversation message, from called KMF, obtain key, again the key that obtains is sent to called UE and called MP respectively.

Certainly, then the call flow with concrete is relevant with calling/called MP how key to be sent to calling/called UE as for calling/called S-CSCF.

Such as:

When the conversation message that receives at originating S-CSCF is 200 message, described originating S-CSCF is carried on described key and sends to caller P-CSCF in 200 message, 200 message that caller P-CSCF will carry described key again send to calling UE, and give caller MP with delivering key.Perhaps,

When the conversation message that receives at originating S-CSCF was PRACK message or UPDATE message, described originating S-CSCF was carried on described key in PRACK message or the UPDATE message and sends to caller AS, gave caller MP by caller AS with described delivering key again; Simultaneously, when originating S-CSCF receives 200 message of returning, described key is carried in 200 message sends to calling UE again.Perhaps,

When terminating S-CSCF receives PRACK message or UPDATE message, the key that obtains is carried in PRACK message or the UPDATE message sends to called P-CSCF, PRACK message or UPDATE message that called P-CSCF will carry described key send to called UE.Perhaps,

When the conversation message that receives at terminating S-CSCF was PRACK message or UPDATE message, terminating S-CSCF was carried on the key that obtains in PRACK message or the UPDATE message and sends to called UE; Simultaneously, when terminating S-CSCF receives 200 message of returning, described key is carried on sends to called AS in 200 message, give called MP by called AS with described delivering key again.

If with the network entity is that AS is an example:

At Calling Side, described network entity is caller AS, and described UE is a calling UE, and described MP is caller MP, and described KMF is caller KMF; Correspondingly, at callee side, described network entity is called AS, and described UE is a called UE, and described MP is called MP, and described KMF is called KMF.That is to say, when caller AS receives conversation message, will from caller KMF, obtain key, again the key that obtains is sent to calling UE and caller MP respectively.After called AS receives conversation message, from called KMF, obtain key, again the key that obtains is sent to called UE and called MP respectively.

Such as: when caller AS receives 200 message, the key that obtains is carried in 200 message sends to caller P-CSCF by originating S-CSCF, by caller P-CSCF described key is carried on 200 message again and sends to calling UE, simultaneously, give caller MP described delivering key; Perhaps,

When the conversation message that receives at caller AS was 200 message, caller AS directly was handed down to caller MP with the key that obtains, and simultaneously, caller AS is carried on described key in 200 message, sends to calling UE by terminating S-CSCF and called P-CSCF.Perhaps,

When the conversation message that receives at called AS is PRACK message or UPDATE message, called AS is carried on described key in PRACK message or the UPDATE message, send to called P-CSCF by terminating S-CSCF, by called P-CSCF described key is carried in PRACK message or the UPDATE message again and sends to called UE, simultaneously, give called MP with described delivering key.Perhaps,

When the conversation message that receives at called AS is PRACK message or UPDATE message, called AS directly is handed down to called MP with the key that obtains, simultaneously, called AS is carried on described key in PRACK message or the UPDATE message, sends to called UE by terminating S-CSCF and called P-CSCF.

In the practical application, before UE and MP obtain key, can also hold consultation to security capabilities between described UE and the network entity.That is:

Calling UE is set up request message to caller AS or caller P-CSCF transmission INVITE session, described INVITE request message carries the media flow security ability information that calling UE provides, and caller AS or caller P-CSCF return 183 response messages that carry the media flow security ability information that caller MP that this side provides supports to calling UE again.And,

When called AS or called P-CSCF receive after the INVITE session sets up request message, request message is set up in the INVITE session that carries the media flow security ability information that called MP that this side provides supports sent to called UE, called UE is returned the 183 conversational response message that the media flow security ability information that self provides is provided to called AS or called P-CSCF again.

In addition, the MP here can be an independent functional entity, also can be a functional unit of functional entitys such as GGSN GGSN or Border Gateway Function entity B GF; MP also can be media resource function entity MRF, and MRF can be made up of media resource controlled function entity MRFC and media resource processing capacity entity MRFP.

The KMF here can be an independent equipment, also can be the functional module among AS, S-CSCF or the HSS.

P-CSCF here or AS or S-CSCF can send a delivering key request message to what MP issued, wherein carry the key that need issue, the parameters such as the term of validity that perhaps also comprise key, MP echo reply message, request here and response message can use Diameter or H.248 agreement carry.

In addition; here the media flow security of caller network side and callee side network protection can be independently; also can be not independently; that is: the caller network side entity is dosed the sign that requires the callee side network that the media flow security service is provided in the request message that mails to the callee side network entity; the callee side network entity is checked through sign just provides user-to-network for called UE media flow security protection service, just can carry out the media flow security protection of user-to-network like this between calling UE and the caller network entity between called UE and the called network entity.

For the scheme of obtaining key that proposes at user-to-network media stream protection situation is described better, be described in detail with several preferred embodiments and system embodiment below.

Method embodiment five

In the present embodiment, the network entity that obtains Calling Side generation key is caller AS, and the entity of generation key is caller KMF, is an independent entity; The network entity that obtains callee side generation key is called AS, and the entity of generation key is called KMF, also is an independent entity.

Fig. 7 is the message flow schematic diagram that the present embodiment Calling Side obtains the media stream protection cryptographic key method.As shown in Figure 7, this method can may further comprise the steps:

Step 701: calling UE sends session to caller P-CSCF and sets up request message, and described session is set up request message and carried the media flow security ability information that calling UE provides.

Step 702: caller P-CSCF continues to send session to originating S-CSCF and sets up request message.

The media flow security ability information that caller P-CSCF can the caller MP that provide be provided is carried can talk about to set up again and is sent to originating S-CSCF in the request message; Caller P-CSCF sends to originating S-CSCF after also session can being set up media flow security ability information deletion in the request message again.

The described session of this step is set up request message for inviting (INVITE) message; described media flow security ability information comprises security algorithm, can also comprise that one or more make up arbitrarily in medium type, secure transfer protocol type and the safe prerequisite that needs protection.

Described safe prerequisite is to be used to refer to the requirement of this session to media flow security, can comprise the intensity sign of the media flow security protection of first entity expectation, such as: compulsory (mandatory), optional (optional), insignificant (none).Described safe prerequisite can also comprise the security negotiation configuration result of expectation and current configuring condition, such as: whether finish negotiation, receive direction and finished security configuration, reception and sending method and all finish security configuration etc.

Step 703: originating S-CSCF is set up request message with described session and is sent to caller AS.

In this step, originating S-CSCF can adopt the initial filter criteria of prior setting, request message is set up in session triggered to caller AS.Then belong to prior art as for how to trigger, repeat no more herein.

Step 704～step 706: caller AS judges the signatory media stream protection business of calling UE, again request message is set up in session and is sent to called network by originating S-CSCF.

In addition, when caller AS judges the signatory media stream protection business of calling UE, can also with calling UE the sign of signatory media stream protection business add session to and set up in the request message.Certainly, owing to present embodiment proposes for the Media Stream of holding Network Transmission at protection, also can not add the described calling UE sign of signatory media stream protection business.Here S-CSCF can oneself check signing service, and does not use the inspection of contracting of AS place, the inspection of also can not contracting.

Here caller AS can delete the media flow security capability set in the INVITE, can not delete yet, but the INVITE that directly will carry Calling Side media flow security capability set mails to terminating S-CSCF, and terminating S-CSCF or called AS can carry out the media flow security capability negotiation with reference to this media flow security ability information.

Step 707～step 710: after response message is set up in the session that the originating S-CSCF reception is returned from called network, response message is set up in described session be transmitted to caller AS, after response message is set up in the session that reception is returned from caller AS, send to caller P-CSCF again.

It is 183 message that response message is set up in session described here.

Step 711: the media flow security ability information that the caller MP that provides is provided caller P-CSCF is carried on session and sets up in the response message, and returns to calling UE.

The all or part of information of the media flow security ability information that caller MP that described caller P-CSCF provides supports for being supported by calling UE.P-CSCF can obtain the media flow security ability information that MP supports by the method for configuration or by the method to caller MP inquiry, and the method for other acquisition repeats no more here.

In the present embodiment, described step 701～step 711 is actual to be the process of between calling UE and caller P-CSCF and the MP security capabilities being held consultation, obtain the other side and can support parameters such as security algorithm, secure transfer protocol, thereby be identified for the media flow security ability information of this session.

Step 712～step 717: calling UE sends conversation message by caller P-CSCF to originating S-CSCF, originating S-CSCF sends described conversation message to caller AS again, the media flow security ability information that caller AS deletion calling UE provides is returned conversation message to originating S-CSCF again, and originating S-CSCF sends to called network with the described conversation message that returns again.

Certainly, caller AS also can not delete the media flow security ability information that calling UE and P-CSCF consult here; Here the media flow security capability set of caller P-CSCF in also can deletion request message, caller AS just can not obtain the media flow security capability set like this, and the process of follow-up AS request key does not also just need reference medium stream security capabilities collection not apply for.

Conversation message described here is a PRACK message.In the practical application, when calling UE receives session when setting up response message, the media flow security ability information that the caller MP that can also provide according to P-CSCF supports is identified for the media flow security ability information of current sessions, and the media flow security ability information that will be used for current sessions is carried on conversation request message.

Step 718～step 719: originating S-CSCF receives the conversational response message that called network returns, and is transmitted to caller AS.

Conversational response message described here is 200 message.

Step 720～step 721: caller AS obtains key from caller KMF, the key that obtains is carried in the conversational response message sends to originating S-CSCF.

In the practical application, caller AS can send secret key request message to caller KMF, and caller KMF generates key and returns to caller AS, and caller AS is carried on conversational response message with the key that obtains again, promptly sends to originating S-CSCF in 200 message.Interactive messages can adopt Diameter or Session Initiation Protocol between caller AS and the caller KMF.

Practical application, caller KMF can also will send to caller AS in the lump at information such as the key term of validity of key, key identifications.

In the practical application, if in step 717, calling UE has been determined to be used for the media flow security ability information of current sessions and to be carried on conversation request message, when caller AS receives the described media flow security ability information that is used for current sessions, just can obtain key from caller KMF according to the media flow security ability information that is used for current sessions in the conversation request message.Certainly, in the practical application, caller AS can not obtain key according to conversation request message yet from caller KMF, and directly obtains key from caller KMF.

Step 722～step 724: originating S-CSCF sends to caller P-CSCF with described conversational response message, and caller P-CSCF continues described conversational response message is sent to calling UE, and gives caller MP with the delivering key that carries in the described conversational response message.

In the practical application, caller P-CSCF can send to described conversational response message earlier after the calling UE, gives caller MP with the delivering key in the described conversational response message again; Also can give caller MP with the delivering key in the described conversational response message earlier, more described conversational response message be sent to calling UE.In addition, caller P-CSCF also can preserve the information such as key that need be handed down to MP earlier here, waits to send to MP again after receiving 200 message that UPDATE message that calling UE sends or called UE send.

At this moment, calling UE and caller MP have obtained key, can utilize this key that Media Stream is protected.Certainly, in the practical application, calling UE also needs to carry out follow-up call flow, such as: calling UE sends UPDATE message by caller P-CSCF, originating S-CSCF to called network, and receives 200 message of returning.How as for follow-up call flow specifically is, can repeat no more with reference to prior art herein.Here 200 message that also can use UPDATE message and return replace PRACK message and 200 message above used, and particular content is similar, also repeats no more here.

In the present embodiment, Fig. 7 is the message flow schematic diagram that calling UE and caller MP obtain media stream protection cryptographic key.In the practical application, callee side can not be called UE and called MP allocation medium stream protection key, and carries out existing common call flow; Callee side also can be called UE and called MP distributing key.That is to say that the process of Calling Side and callee side distributing key is separate, a side distributing key can only be arranged, an other side is carried out according to existing common call flow, also can both sides distributing key all.

For callee side is the situation of called UE and called MP distributing key, can utilize and the Calling Side similar methods.Fig. 8 is the message flow schematic diagram that callee side obtains the media stream protection cryptographic key method.As shown in Figure 8, this method can may further comprise the steps:

Step 801～step 802: terminating S-CSCF receives and sets up request message from the session of caller network, and is transmitted to called AS.

Request message is set up in session described here can be INVITE.

Similar to step 702, terminating S-CSCF can adopt the initial filter criteria of prior setting, request message is set up in session triggered to called AS.Then belong to prior art as for how to trigger, repeat no more herein.

Step 803～step 805: it is signatory that called AS judges called UE, session set up request message again and send to called P-CSCF by terminating S-CSCF.

Called AS also can not judge the process that called UE is signatory.

Step 806: the media flow security ability information that the called MP that provides is provided called P-CSCF is added described session to and is set up in the message, sends to called UE again.

Step 807: called UE is returned session to called P-CSCF and is set up response message, and described session is set up response message and carried the media flow security ability information that called UE provides.

It is 183 message that response message is set up in session described here.When called UE receives session when setting up request message, the media flow security ability information that need provide is provided for the media flow security ability information that can support according to the called MP that called P-CSCF in the message will provide and the media flow security ability information that self can support.Here called P-CSCF doses the media flow security ability information of confirming in 183 response messages after also will determining the media flow security ability information of this session use.

Step 808～step 809: called P-CSCF sets up response message with session and sends to terminating S-CSCF, and terminating S-CSCF is set up session response message again and is transmitted to called AS.

Here,, can also set up the media flow security ability information that is identified for current sessions in the media flow security ability information of carrying the response message, and be carried on session and set up in the response message from session when called P-CSCF receives session when setting up response message.Certainly, called here P-CSCF also can delete the media flow security capability set in the response message, and called like this AS just can not obtain the media flow security capability set, and the process of follow-up AS request key does not just need reference medium stream security capabilities collection to apply for yet.

Step 810～step 812: the media flow security ability information in the response message is set up in called AS deletion session, by terminating S-CSCF response message is set up in session again and is sent to the caller network.

Certainly, called here AS also can not delete the media flow security ability information.

Step 813～step 814: terminating S-CSCF receives the conversation message from the caller network, and described conversation message is transmitted to called AS.

Conversation message described here is a PRACK message.

Step 815～step 816: called AS obtains key from called KMF, and the key that obtains is added in the conversation message, sends to terminating S-CSCF again.

Similar to step 720～step 721 among present embodiment Fig. 7, when needs obtain key from called KMF, called AS also can send secret key request message to called KMF, called KMF generates key and returns to called AS, called AS is carried on conversation request message with the key that obtains again, promptly sends to terminating S-CSCF in the PRACK message.Interactive messages can adopt Diameter or Session Initiation Protocol between called AS and the called KMF.

Similarly, called KMF also can will send to called AS at information such as the key term of validity of key, key identifications in the lump.

Step 817～step 819: terminating S-CSCF sends to called P-CSCF with session message, and called P-CSCF sends to called UE with described conversation message again, and gives called MP with the delivering key in the described conversation message.

Certainly, if conversation message also carries information such as the key term of validity at key, key identification, so, called P-CSCF also needs information such as the described key term of validity, key identification are handed down to called MP in the lump.Certainly, called P-CSCF also can also be with media flow security ability information in the session message, as: information such as medium type, safe transmission mode are handed down to called MP in the lump.

In addition, called here P-CSCF also can preserve the information such as key that need be handed down to called MP earlier, sends to MP again after waiting 200 message of receiving UPDATE message that terminating S-CSCF sends or called UE.

At this moment, the media stream protection cryptographic key that called UE and called MP obtain can utilize this key that the Media Stream of transmission is protected.In the practical application, after described step 819, also need to carry out follow-up call flow, such as: called UE sends 200 message by terminating S-CSCF, called P-CSCF to the caller network, receives from the UPDATE message of caller network etc., repeats no more herein.

Method embodiment six

In the present embodiment, the network entity that obtains Calling Side generation key is an originating S-CSCF, and that the generation key is caller KMF; The network entity that obtains callee side generation key is a terminating S-CSCF, and that the generation key is called KMF.

Fig. 9 is the message flow schematic diagram that the present embodiment Calling Side obtains the media stream protection cryptographic key method.As shown in Figure 9, this method can may further comprise the steps:

Step 901～step 902: calling UE sends session by caller P-CSCF to originating S-CSCF and sets up request message, and described session is set up request message and carried the media flow security ability information that calling UE provides.

It is INVITE that request message is set up in session described here, and described step 901～step 902 is identical with step 701～step 702 among the embodiment five, repeats no more herein.

Step 903: originating S-CSCF is set up request message with described session and is sent to caller AS.

Step 903 described here is identical with step 703 among the embodiment five, repeats no more herein.

Step 904～step 906: caller AS judges the signatory media stream protection business of calling UE, again request message is set up in session and is sent to called network by originating S-CSCF.

Step 904 described here～step 906 is identical with step 704～step 706 among the embodiment five, repeats no more herein.

Step 907～step 908: the originating S-CSCF reception is set up response message from the session that called network returns, and directly sends to caller P-CSCF.

It is 183 message that response message is set up in session described here, and its flow process is similar to step 707～step 710 of embodiment five, just can no longer pass through caller AS.

Step 909: the media flow security ability information that the caller MP that provides is provided caller P-CSCF is carried on session and sets up in the response message, and returns to calling UE.

This step is identical with step 711 among the embodiment five, repeats no more herein.

Step 910～step 913: calling UE sends conversation message by caller P-CSCF to originating S-CSCF, and the media flow security ability information that calling UE provides in the originating S-CSCF deletion conversation message sends to called network with described conversation message again.The originating S-CSCF here also can not deleted the media flow security ability information in the conversation message.

Conversation message described here is a PRACK message.In the practical application, when calling UE receives session when setting up response message, the media flow security ability information that the caller MP that can also provide according to caller P-CSCF supports is identified for the media flow security ability information of current sessions, and the media flow security ability information that will be used for current sessions is carried on conversation request message.

Step 914: originating S-CSCF receives the conversational response message that called network returns.

Conversational response message described here is 200 message.

Step 915～step 916: originating S-CSCF obtains key from caller KMF, the key that obtains is carried on sends to caller P-CSCF in the conversational response message.

Similar to embodiment four, here, originating S-CSCF can send secret key request message to caller KMF, and caller KMF generates key and returns to originating S-CSCF; Originating S-CSCF is carried on conversational response message with the key that obtains again, promptly sends to caller P-CSCF in 200 message.Interactive messages can adopt Diameter or Session Initiation Protocol between originating S-CSCF and the caller KMF.

Practical application, caller KMF can also will send to originating S-CSCF in the lump at information such as the key term of validity of key, key identifications.

Step 917～step 918: caller P-CSCF sends to calling UE with described conversational response message, and gives caller MP with the delivering key in the described conversational response message.

At this moment, calling UE and caller MP have obtained key, can utilize described key that the Media Stream of transmission is protected.

Identical with embodiment five, calling UE also needs to carry out follow-up call flow in the present embodiment, repeats no more herein.

In addition, caller P-CSCF also can preserve the information such as key that need be handed down to caller MP earlier here, sends to MP again after waiting 200 message of receiving UPDATE message that calling UE sends or called UE.

In the present embodiment, Fig. 9 is the message flow schematic diagram that calling UE and caller MP obtain media stream protection cryptographic key.For callee side is the situation of called UE and called MP distributing key, can utilize and the Calling Side similar methods.

Figure 10 is the message flow schematic diagram that callee side obtains the media stream protection cryptographic key method in the present embodiment.As shown in figure 10, this method can comprise step:

Step 1001～step 1002: terminating S-CSCF receives and sets up request message from the session of caller network, and is transmitted to called AS.

Request message is set up in session described here can be INVITE, and described step 1001～step 1002 is identical with step 801～step 802 among the embodiment five, repeats no more herein.

Step 1003～step 1005: it is signatory that called AS judges called UE, session set up request message again and send to called P-CSCF by terminating S-CSCF.

Called AS or S-CSCF also can not judge the process that called UE is signatory.Step 1003 described here～step 1005 is identical with step 803～step 805 among the method embodiment five, repeats no more herein.

Step 1006: the media flow security ability information that the called MP that provides is provided called P-CSCF is added described session to and is set up in the message, sends to called UE again.

This step is identical with step 806 among the embodiment five, repeats no more herein.

Step 1007: called UE is returned session to called P-CSCF and is set up response message, and described session is set up response message and carried the media flow security ability information that called UE provides.

This step is identical with step 807 in the method enforcement five, and it is 183 message that response message is set up in described session, repeats no more herein.

Step 1008～step 1010: called P-CSCF sets up response message with described session and sends to terminating S-CSCF, and terminating S-CSCF is deleted described session and set up media flow security ability information in the response message, sends to the caller network again.

Terminating S-CSCF also can not deleted described session and set up media flow security ability information in the response message.

Step 1011～step 1013: terminating S-CSCF receives the conversation message from the caller network, obtains key from called KMF again, and the key that obtains is added in the conversation message, and send to called P-CSCF.

Conversation message described here is a PRACK message.

Step 1014～step 1015: called P-CSCF sends to called UE with described conversation message again, and gives called MP with the delivering key in the described conversation message.

At this moment, the media stream protection cryptographic key that called UE and called MP obtain can utilize this key that the Media Stream of transmission is protected.Certainly, after the step 1015, actual also need to carry out follow-up call flow, such as: called UE sends 200 message by terminating S-CSCF, called P-CSCF to the caller network, receives from the UPDATE message of caller network etc., repeats no more herein.

Method embodiment seven

In the present embodiment, the network entity that obtains Calling Side generation key is caller AS, and the entity that generates key is caller KMF, and described MP is caller MP; The network entity that obtains callee side generation key is called AS, and that the generation key is called KMF.

In addition, in the present embodiment, described caller MP is caller MRF, and described called MP is called MRF.MRF described here can initiate a conversation message again when receiving conversation message.Such as: when receiving INVITE, MRF can regenerate an other INVITE, again the INVITE that regenerates is continued to be transferred to next entity.Belonging to prior art as for how regenerating conversation message, repeating no more herein.

In the present embodiment only as the situation of back-to-back user agent's B2BUA as an example with AS; In actual the enforcement, AS also can only revise the relevant information of media flow security in the calling of sending of Calling Side, and need not initiate a new session flow process again; In addition, AS continues to consult with Calling Side after can also consulting to finish with callee side earlier again, and idiographic flow is similar to be repeated no more here.

Figure 11 is the message flow schematic diagram that the present embodiment Calling Side obtains media stream protection cryptographic key.As shown in figure 11, this method may further comprise the steps:

Step 1101: calling UE sends session to originating S-CSCF and sets up request message, and described session is set up request message and carried the media flow security ability information that calling UE provides.

This step is identical with step 701～step 702 among the embodiment five, calling UE also needs to send session by caller P-CSCF and sets up request message, and just in the present embodiment, described caller P-CSCF only is used for the forwarding of message, can't issue key, so neglect description to P-CSCF.

It is INVITE that request message is set up in the described session of this step, but in order to distinguish with follow-up INVITE, INVITE described here is INVITE[1].

Step 1102: originating S-CSCF is set up request message with described session and is sent to caller AS.

This step is identical with the step 703 of embodiment five, repeats no more herein.

Step 1103～step 1105: it is signatory that caller AS judges calling UE, and the session that self is regenerated is set up request message and sent to called network by originating S-CSCF again.

Here caller AS or the originating S-CSCF inspection of also can not contracting.

Step 1103 described here～step 1105 is similar to the step 704～step 706 among the embodiment five, and just caller AS has regenerated a session and set up request message, and request message is set up in the described session that regenerates can be designated as INVITE[2].

Step 1106～step 1107: after response message is set up in the session that the originating S-CSCF reception is returned from called network, response message is set up in described session be transmitted to caller AS.

It is 183 message that response message is set up in session described here, is at INVITE[2] response message, can be designated as 183[2] message.

Step 1108～step 1109: caller AS regenerates session and sets up response message, the described session that regenerates is set up response message and is carried the media flow security ability information that caller MRF provides, and response message is set up in the described session that regenerates sent to originating S-CSCF, send to calling UE by originating S-CSCF.

Here, it is at INVITE[1 that response message is set up in the session that caller AS regenerates] response message, can be designated as 183[1] message.

The media flow security ability information that described MRF provides can be all or part of information that can be supported by calling UE.

Step 1110～step 1111: calling UE sends conversation message to originating S-CSCF, and originating S-CSCF sends to caller AS with described conversation message again.

Conversation message described here is a PRACK message, distinguishes for the PRACK message that generates with follow-up caller AS, can be designated as PRACK[1].

Step 1112～step 1113: caller AS regenerates conversation message, and the conversation message that regenerates is sent to originating S-CSCF, has originating S-CSCF to send to called network again.

Here, the PRACK that regenerates of described caller AS can be designated as PRACK[2] message.

Step 1114～step 1115: originating S-CSCF receives the conversational response message from called network, and described conversational response message is sent to caller AS.

Here, described conversational response message is 200 message, because this message is at PRACK[2], it can be designated as 200[2] message.

Step 1116～step 1119: caller AS obtains key from caller KMF, give caller MRF with the delivering key that obtains, and regenerate conversational response message, and be carried in the conversational response message that regenerates obtaining key, send to calling UE by originating S-CSCF.

The conversational response message that caller AS described here regenerates is 200 message, because this message is at PRACK[1], it can be designated as 200[1].

At this moment, calling UE and caller MRF have obtained key, can utilize this key that the Media Stream of transmission is protected.

In the present embodiment, Figure 11 is the message flow schematic diagram that calling UE and caller MRF obtain media stream protection cryptographic key.In the practical application, if callee side will can utilize the Calling Side similar methods for called UE and called MRF distributing key.Figure 12 is the message flow schematic diagram that callee side obtains media stream protection cryptographic key in the present embodiment.As shown in figure 12, this method can may further comprise the steps:

Step 1201～step 1202: terminating S-CSCF receives and sets up request message from the session of caller network, and is transmitted to called AS.

For corresponding with above-mentioned Calling Side, it is INVITE[2 that request message is set up in the session that terminating S-CSCF described here receives].

Step 1203～step 1205: it is signatory that called AS judges called UE, regenerate session again and set up request message, and the media flow security ability information that called MRF provides is carried on the described session that regenerates sets up in the request message, send to called UE by terminating S-CSCF.

Called AS or terminating S-CSCF also can not go out the signatory inspection of called UE.

Here, set up request message and distinguish mutually, the session that called AS regenerates can be set up request message and be designated as INVITE[3] in order to regenerate session with above-mentioned caller AS.

Step 1206: called UE is returned session to terminating S-CSCF and is set up response message, and described session is set up response message and carried the media flow security ability information that called UE provides.

It is 183 message that response message is set up in session described here, owing to be at INVITE[3] response response message, it can be designated as 183[3] message.

Step 1207～step 1209: terminating S-CSCF is set up response message with the session that receives and is sent to called AS, called AS regenerates session again and sets up response message, and response message is set up in the session that regenerates sent to terminating S-CSCF, send to the caller network by terminating S-CSCF then.

Here, it is at prior INVITE[2 that response message is set up in the session that described called AS regenerates] message, it can be designated as 183[2].

Step 1210～step 1211: terminating S-CSCF receives the conversation message from the caller network, and described conversation message is transmitted to called AS.

Conversation message described here is a conversation request message, i.e. the PRACK[2 that sends of caller network] message.

Step 1212～1215: called AS obtains key from called KMF, gives called MRF with the delivering key that obtains, and regenerates conversation message, and the described key that obtains is carried on the conversation message that regenerates, and sends to called UE by terminating S-CSCF.

Here, the conversation message that regenerates of described called AS is PRACK[3] message.

At this moment, the key that called UE and called MRF obtain just can utilize this key that the Media Stream of transmission is protected.

Certainly, after the step 1215, called UE also needs to carry out follow-up call flow, such as: called UE sends 200 message by terminating S-CSCF and called AS to the caller network, and receives UPDATE message etc. again.In follow-up call flow, called AS still can regenerate the conversation message that sends from terminating S-CSCF, repeats no more herein.PRACK message here and 200 corresponding response messages can be substituted by UPDATE message and 200 corresponding response messages, and idiographic flow is similar, repeats no more here.

Method embodiment eight

In the present embodiment, the network entity that obtains Calling Side generation key is an originating S-CSCF, and the entity that generates key is caller KMF; The network entity that obtains Calling Side generation key is a terminating S-CSCF, and the entity that generates key is KMF.

In addition, in the present embodiment, described caller MP is caller MRF, and called MP is called MRF.

Figure 13 is the message flow schematic diagram that the present embodiment Calling Side obtains the media stream protection cryptographic key method.As shown in figure 13, this method can may further comprise the steps:

Step 1301: calling UE sends session to originating S-CSCF and sets up request message, and described session is set up request message and carried the media flow security ability information that calling UE provides.

This step is identical with step 1101 among the embodiment seven, and it is INVITE[1 that request message is set up in session described here], repeat no more herein.

Step 1302: originating S-CSCF is set up request message with described session and is sent to caller AS.

This step is identical with the step 1102 of embodiment seven, repeats no more herein.

Step 1303～step 1305: it is signatory that caller AS judges calling UE, and the session that self is regenerated is set up request message and sent to called network by originating S-CSCF again.

Step 1303 described here～step 1305 is identical with step 1103～step 1105 of embodiment seven, and request message is set up in the described session that regenerates can be designated as INVITE[2], repeat no more herein.

Step 1306～step 1307: after response message is set up in the session that the originating S-CSCF reception is returned from called network, response message is set up in described session be transmitted to caller AS.

Step 1306 described here～step 1307 is identical with step 1106～step 1107 among the embodiment seven, and it is 183[2 that response message is set up in described session] message, repeat no more herein.

Step 1308～step 1309: caller AS regenerates session and sets up response message, the described session that regenerates is set up response message and is carried the media flow security ability information that caller MRF provides, and response message is set up in the described session that regenerates sent to originating S-CSCF, send to calling UE by originating S-CSCF.

Step 1308 described here～step 1309 is identical with step 1108～step 1109 of embodiment seven, and it is 183[1 that response message is set up in the session that described caller AS regenerates] message.

Step 1310～step 1312: calling UE sends conversation message to originating S-CSCF, and originating S-CSCF obtains key from caller KMF, the key that obtains is carried in the described conversation message, and sends to caller AS.

Conversation message described here is a conversation request message, i.e. PRACK message.Distinguish for the PRACK message that regenerates with follow-up caller AS, can be designated as PRACK[1] message.

Step 1313～step 1315: caller AS will give caller MRF from the delivering key the conversation message that originating S-CSCF is sent, regenerate conversation message again, and the conversation message that regenerates sent to originating S-CSCF, send to called network by originating S-CSCF then.

The conversation message that regenerates described here can be designated as PRACK[2].

Step 1316～step 1319: originating S-CSCF receives the conversational response message from called network, described conversational response message is sent to caller AS, and receiving the conversational response message that caller AS regenerates, the key that will obtain in advance is carried in the conversational response message that described caller AS regenerates and sends to calling UE then.

Conversational response message described here is at PRACK[2] conversational response message, i.e. 200[2] message.The conversational response message that described caller AS regenerates is at PRACK[1] conversational response message, i.e. 200[1].

At this moment, calling UE and caller MRF have obtained key, can utilize this key that the Media Stream of transmission is protected.Certainly, after the step 1319, also need to carry out follow-up call flow, repeat no more herein.

In the present embodiment, Figure 13 is the message flow schematic diagram that calling UE and caller MRF obtain media stream protection cryptographic key.In the practical application, if callee side will can utilize the Calling Side similar methods for called UE and called MRF distributing key.

Figure 14 is the message flow schematic diagram that callee side obtains media stream protection cryptographic key in the present embodiment.As shown in figure 14, this method can may further comprise the steps:

Step 1401～step 1402: terminating S-CSCF receives and sets up request message from the session of caller network, and is transmitted to called AS.

Step 1401 described here～step 1402 is identical with step 1201～step 1202 among the embodiment seven, and it is INVITE[2 that request message is set up in described session], repeat no more herein.

Step 1403～step 1405: it is signatory that called AS judges called UE, regenerate session again and set up request message, and the media flow security ability information that called MRF provides is carried on the described session that regenerates sets up in the request message, send to called UE by terminating S-CSCF.

Step 1403 described here～step 1405 is identical with step 1203～step 1205 among the embodiment seven, and it is INVITE[3 that request message is set up in the session that described called AS regenerates], repeat no more herein.

Step 1406: called UE is returned session to terminating S-CSCF and is set up response message, and described session is set up response message and carried the media flow security ability information that called UE provides.

This step is identical with the step 1206 of embodiment seven, and it is 183[3 that response message is set up in described session] message.

Step 1407～step 1409: terminating S-CSCF is set up response message with the session that receives and is sent to called AS, called AS regenerates session again and sets up response message, and response message is set up in the session that regenerates sent to terminating S-CSCF, send to the caller network by terminating S-CSCF then.

Step 1407 described here～step 1409 is identical with step 1207～step 1209 among the embodiment seven, and it is 183[2 that response message is set up in the session that described called AS regenerates], repeat no more herein.

Step 1410～step 1411: terminating S-CSCF receives the conversation message from the caller network, and described conversation message is transmitted to called AS.

Step 1412: called AS regenerates conversation message, and the conversation message that regenerates is sent to terminating S-CSCF.

For with the PRACK[2 that receives] message distinguishes, the conversation message that called AS described here regenerates can be designated as PRACK[3].

Step 1413～step 1414: terminating S-CSCF obtains key from called KMF, and the key that obtains is carried in the described conversation message that regenerates sends to called UE.

Step 1415: called UE sends conversational response message to terminating S-CSCF.

Conversational response message described here is at PRACK[3] conversational response message, i.e. 200[3] message.

Step 1416～step 1419: the key that terminating S-CSCF will obtain in advance is carried on and sends to called AS in the conversational response message, called AS gives called MRF with the delivering key in the described conversational response message, and regenerate conversational response message, the conversational response message that regenerates is sent to the caller network by terminating S-CSCF.

At this moment, called UE and called MFR have obtained key, can utilize this key that the Media Stream of transmission is protected.

The method of obtaining key that proposes at the Media Stream situation of above-mentioned protection user-to-network transmission, the present invention also proposes a kind of system that obtains media stream protection cryptographic key.

Figure 15 is the basic structure schematic diagram of this system.As shown in figure 15, this system comprises:

UE1501 is used to receive the key that network entity sends;

Network entity 1502 is used to receive conversation message, obtains key from KMF 1503, and sends to UE1501 and MP1504;

KMF1503 is used to generate key;

MP1504 is used to receive the key that network entity sends.

In the practical application, described network entity 1502 can be S-CSCF, also can be AS.

This system can realize obtaining the system of media stream protection cryptographic key for Calling Side, also can realize obtaining the system of protection key for callee side.If be Calling Side, then described UE1501 is a calling UE, and described network entity 1502 is originating S-CSCF or caller AS, and described KMF1503 is caller KMF, and described MP1504 is caller MP.

Certainly, if network entity is S-CSCF, this system may further include AS, can further include P-CSCF; If network entity is AS, this system may further include S-CSCF, can further include P-CSCF.KMF of the present invention can be an independent entity, also can be a functional unit among CSCF, AS or the HSS.

System embodiment three

Figure 16 is the basic structure schematic diagram of system embodiment three.As shown in figure 16, native system embodiment comprises: calling UE 1501, originating S-CSCF 1502A, caller KMF1503, caller MP1504, caller P-CSCF1505.Wherein, described caller P-CSCF is used to transmit interactive messages between calling UE 1501 and the originating S-CSCF 1502A, also be used for giving caller MP1504 with delivering key from caller S-CSCF conversation message, other entity is identical with the function and the structure of the described corresponding entity of Figure 15, repeats no more herein.

When needs obtain media stream protection cryptographic key; calling UE 1501 sends conversation message by caller P-CSCF1505 to originating S-CSCF 1502A; originating S-CSCF 1502A obtains key from caller KMF1503; and the key that obtains sent to caller P-CSCF1505 by conversational response message, caller P-CSCF1505 sends to described key calling UE 1501 and caller MP again.

Certainly, each entity described in the present embodiment also is used for and carries out other relevant function of call flow, and the function of its realization or flow process can repeat no more referring to the above-mentioned method embodiment of the present invention herein.

Certainly, in the practical application, this system can further include caller AS, is used to check whether calling UE is signatory, as for how to check can repeat no more referring to above-mentioned method embodiment herein.

In addition, the described caller MP1504 of native system embodiment receives the key that issues from caller P-CSCF1505, and in the practical application, described caller MP1504 also can directly obtain the key that issues from originating S-CSCF, caller AS.

System implementation four

Figure 17 is the basic structure schematic diagram of native system embodiment.As shown in figure 17, native system embodiment comprises: calling UE 1501, caller AS1502B, caller KMF1503, caller MP1504.

This system can also comprise caller P-CSCF and originating S-CSCF, but different with system embodiment four is, originating S-CSCF described here no longer obtains from caller KMF, can be only as the entity of transmitting message, other entity is identical with the function and the structure of the described corresponding entity of Figure 15, repeats no more herein.

When needs obtain media stream protection cryptographic key; calling UE 1501 sends conversation message by caller P-CSCF and originating S-CSCF to caller AS1502B; caller AS1502B obtains key from caller KMF1503; and the key that obtains directly is handed down to caller MP1504; and described message is carried in the conversational response message, send to calling UE 1501 by originating S-CSCF and P-CSCF.

Similar to system embodiment three, in the practical application, caller AS1502B also can also repeat no more with doing that calling UE 1501 is checked signatory entity herein.

Equally, the described caller AS of native system embodiment can also give caller MP with delivering key by originating S-CSCF or caller P-CSCF.

System embodiment three of the present invention and system embodiment four all are that example describes with the Calling Side, and in the practical application, if callee side need be called UE and called MP distributing key, the structure of its system is similar to Calling Side, repeats no more herein.

Among the present invention; no matter be the Media Stream that transmits to the user for the protection user and propose obtain encryption key method; or the method for obtaining key that proposes for the Media Stream of protecting the user-to-network transmission; in described INVITE; described media flow security ability information is except comprising security algorithm, can also comprise that one or more make up arbitrarily in the medium type that needs protection, secure transfer protocol type, the safe prerequisite.The user is in mutual other message of user or user-to-network, described media flow security ability information can comprise that also one or more make up arbitrarily in medium type, secure transfer protocol type, the safe prerequisite, and then the realization with concrete is relevant with security algorithm as for whether comprising key.

The key that network side generates can be carried in the media flow security ability information and send to the other side.At this moment, can also comprise parameters such as the key term of validity in the described media flow security ability information.If a plurality of Media Streams that need protection are arranged, can also generate different keys at each different Media Stream at every turn, can also comprise key identification in the described media flow security ability information, to distinguish corresponding Media Stream.

The media flow security that described security algorithm can define in rfc 4568 is described in the agreement (SDES) and is carried as the crypto-suite parameter in the a=crypto header field; The key of described generation, key identification, the key term of validity etc. can the key-params parameter of inline (inline) sub-header field be carried in SDES agreement a=crypto header field.

If adopt the multimedia internet key to consult (MIKEY) management agreement, security algorithm wherein, comprise that the safe context of key length, key generation rate etc. can be carried in the parameter that defines in security strategy load in the RFC 3830MIKEY agreement (the Security Policy payload) field.The key of described generation, the key term of validity etc. can be carried in cipher key delivery load among the MIKEY (KEMAC, the Key datatransport payload) field.Whole M IKEY message then can be carried in the a=key-mgmt SDP attribute field of RFC4567 regulation.

Described security algorithm also can be expanded a security algorithm header field and carry in Session Initiation Protocol; Equally, the key of described generation, key identification, the key term of validity etc. also can be carried by the header field of expansion correspondence in Session Initiation Protocol comes.

Use embodiment of the invention scheme, owing to can generate key by network side, and give the entity of Media Stream that needs protection with the delivering key that generates, thus reach the purpose that the Media Stream of transmission is protected.In addition, because key is by network side entity or functional unit, promptly KMF generates key, can satisfy the actual demand of third party's Lawful Interception.

In sum, more than be preferred embodiment of the present invention only, be not to be used to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. a method of obtaining media stream protection cryptographic key is characterized in that, this method may further comprise the steps:

2. method according to claim 1 is characterized in that, described step a is specially:

After a1, caller network entity are received the Temporary Response affirmation PRACK request message that calling UE sends or are upgraded the UPDATE request message, obtain the key that this adnation becomes to caller key management function entity KMF, and described key is sent to the called network entity by PRACK or UPDATE request message;

After a2, called network entity are received PRACK or UPDATE request message; obtain the key that this adnation becomes to called key management function entity KMF; determine media stream protection cryptographic key according to the key of this adnation one-tenth and the key of Calling Side generation again, and media stream protection cryptographic key is sent to called UE by PRACK or UPDATE request message.

3. method according to claim 2 is characterized in that, described caller network entity is calling conversation control function entity S-CSCF or caller application server AS, and described called network entity is terminating S-CSCF or called AS;

Described originating S-CSCF or caller AS to the method that caller KMF obtains the key of this adnation one-tenth are: originating S-CSCF or caller AS send secret key request message to caller KMF, and caller KMF returns to originating S-CSCF or caller AS with the key that generates by key response message;

Described terminating S-CSCF or called AS to the method that called KMF obtains the key of this adnation one-tenth are: terminating S-CSCF or called AS send secret key request message to called KMF, and called KMF returns to terminating S-CSCF or called AS with the key that generates by key response message.

4. method according to claim 2, it is characterized in that, described called network entity is terminating S-CSCF or called AS, and then described terminating S-CSCF of step a2 or called AS determine that the method for media stream protection cryptographic key is: the key that the key that terminating S-CSCF or called AS directly generate Calling Side becomes with this adnation is as media stream protection cryptographic key;

After the described called UE of step a2 receives described conversation request message; this method further comprises: the key that the cipher key derivative that the key that called UE generates according to the Calling Side in the described conversation request message becomes with this adnation makes new advances, and with the key that derives as media stream protection cryptographic key.

5. method according to claim 2 is characterized in that, described called network entity is terminating S-CSCF or called AS, and then described terminating S-CSCF of step a2 or called AS determine that the method for media stream protection cryptographic key is:

The key that the cipher key derivative that the key that terminating S-CSCF or called AS generate according to Calling Side becomes with this adnation makes new advances, and with the key that derives as media stream protection cryptographic key.

6. method according to claim 1 is characterized in that, described step b is specially:

After b1, called network entity were received 200 response messages that called UE returns, the key that this side is generated in advance was carried in described 200 response messages, and sends to the caller network entity;

After b2, caller network entity were received described 200 response messages, the key that key that generates in advance according to this side and callee side generate was determined media stream protection cryptographic key, and media stream protection cryptographic key added in described 200 response messages sent to calling UE.

7. method according to claim 6, it is characterized in that, the described caller network entity of step b2 is originating S-CSCF or caller AS, and described originating S-CSCF or caller AS determine that the method for media stream protection cryptographic key is: the key that key that originating S-CSCF or caller AS directly become this adnation and callee side generate is as media stream protection cryptographic key;

After the described calling UE of step b2 received conversational response, this method further comprised: the key that the cipher key derivative that key that calling UE becomes according to this adnation in the conversational response message and callee side generate makes new advances, and with the key that derives as media stream protection cryptographic key.

8. method according to claim 6 is characterized in that, described caller network entity is originating S-CSCF or caller AS, and described originating S-CSCF or caller AS determine that the method for media stream protection cryptographic key is:

The key that the cipher key derivative that key that originating S-CSCF or caller AS become according to this adnation and callee side generate makes new advances, and with the key that derives as media stream protection cryptographic key.

9. method according to claim 1 is characterized in that, the described calling UE of step a sends before the described conversation request message, and this method further comprises:

The session that the media flow security ability information that self provides will be provided calling UE is set up request message and is sent to called UE by network entity, and described session is set up request message for inviting the INVITE request message; The media flow security ability information that called UE provides according to calling UE is provided by the media flow security ability information that self need provide, and the media flow security ability information that provides is carried on session sets up in the response response message, return to calling UE by network entity, it is 183 response messages that response message is set up in described session.

10. method according to claim 9, it is characterized in that, described network entity comprises caller network entity and called network entity, when the caller network entity receives described INVITE request message, this method further comprises: the caller network entity is judged the signatory media flow security business of calling UE, the sign of the signatory media flow security business of calling UE is added in the described INVITE request message, send to the called network entity again;

11. method according to claim 9 is characterized in that, described media flow security ability information comprises the media flow security algorithm, comprises also that perhaps one or more make up arbitrarily in medium type, secure transfer protocol type and the safe prerequisite that needs protection.

12. method according to claim 9 is characterized in that, described media flow security ability information is carried among Session Description Protocol SDP or the Session initiation Protocol SIP.

13. a system that obtains media stream protection cryptographic key is characterized in that, this system comprises:

14. system according to claim 13 is characterized in that,

Described system also comprises KMF, and described KMF comprises caller KMF and called KMF, wherein,

Caller KMF is used to generate key and sends to the caller network entity;

Called KMF is used to generate key and sends to the called network entity.

Described network entity comprises caller network entity and called network entity, wherein,

Described caller network entity is originating S-CSCF or caller AS, is used to receive the conversation request message that calling UE sends, and obtains key from caller KMF, and sends to the called network entity; Also be used to receive the conversational response message that called UE sends, determine media stream protection cryptographic key and send to calling UE by response message;

Described called network entity is terminating S-CSCF or called AS, is used to receive the conversation request message from the caller network entity, obtains key from called KMF, determines media stream protection cryptographic key and sends to called UE by conversation request message; Also be used to receive the conversational response message that called UE is returned, the key that this adnation is become is carried on and sends to the caller network entity in the conversational response message.

15. system according to claim 14 is characterized in that, uses Diameter or Session Initiation Protocol to carry out communication between described network entity and the KMF.

16. system according to claim 14 is characterized in that, described caller KMF is the functional module among originating S-CSCF or the caller AS, and described called KMF is the functional module among terminating S-CSCF or the called AS.

17. a method of obtaining media stream protection cryptographic key is characterized in that, this method may further comprise the steps:

18. method according to claim 17, it is characterized in that described network entity is a caller service call session control function entity S-CSCF/ terminating S-CSCF, described UE is calling UE/called UE, described MP is the called MP of caller MP/, and described KMF is the called KMF of caller KMF/.

19. method according to claim 18 is characterized in that, the conversation message that described terminating S-CSCF receives is PRACK message or UPDATE message, and described terminating S-CSCF with the method that the key that obtains sends to called UE is:

Terminating S-CSCF is carried on described key in PRACK message or the UPDATE message and sends to called P-CSCF, and PRACK message or UPDATE message that called P-CSCF will carry described key send to called UE.

20. method according to claim 18 is characterized in that, the conversation message that described terminating S-CSCF receives is PRACK message or UPDATE message, and described terminating S-CSCF with the method that the key that obtains sends to called MP is:

Terminating S-CSCF is carried on described key in PRACK message or the UPDATE message and sends to called P-CSCF, and called P-CSCF gives called MP with described delivering key again.

21. method according to claim 18 is characterized in that, the conversation message that described originating S-CSCF receives is 200 message, and described originating S-CSCF with the method that the key that obtains sends to calling UE is:

Described originating S-CSCF is carried on described key and sends to caller P-CSCF in 200 message, and 200 message that caller P-CSCF will carry described key send to calling UE.

22. method according to claim 18 is characterized in that, the conversation message that described originating S-CSCF receives is 200 message, and described originating S-CSCF with the method that the key that obtains sends to caller MP is:

Described originating S-CSCF is carried on described key and sends to caller P-CSCF in 200 message, and caller P-CSCF gives caller MP with described delivering key.

23. method according to claim 18 is characterized in that, the conversation message that described originating S-CSCF receives is PRACK message or UPDATE message, and described originating S-CSCF with the method that the key that obtains sends to caller MP is:

Originating S-CSCF is carried on described key in PRACK message or the UPDATE message and sends to caller AS, gives caller MP by caller AS with described delivering key again.

24. method according to claim 18 is characterized in that, the conversation message that described terminating S-CSCF receives is PRACK message or UPDATE message, and described terminating S-CSCF with the method that described key sends to called MP is:

Terminating S-CSCF is carried on described key and sends to called AS in 200 message, gives called MP by called AS with described delivering key again.

25. method according to claim 17 is characterized in that, described network entity is the called AS of caller AS/, and described UE is calling UE/called UE, and described MP is the called MP of caller MP/, and described KMF is the called KMF of caller KMF/.

26. method according to claim 25 is characterized in that, the conversation message that described caller AS receives is 200 message, and described caller AS with the method that the key that obtains sends to calling UE is:

Described caller AS is carried on described key in 200 message and sends to caller P-CSCF by originating S-CSCF, and 200 message that caller P-CSCF will carry described key send to calling UE.

27. method according to claim 25 is characterized in that, the conversation message that described caller AS receives is 200 message, and described caller AS with the method that the key that obtains sends to caller MP is:

Described caller AS is carried on described key in 200 message and sends to caller P-CSCF by originating S-CSCF, and caller P-CSCF gives caller MP with described delivering key.

28. method according to claim 25 is characterized in that, the conversation message that described called AS receives is PRACK message or UPDATE message, and described called AS with the method that the key that obtains sends to called UE is:

Called AS is carried on described key in PRACK message or the UPDATE message, sends to called P-CSCF by terminating S-CSCF, and PRACK message or UPDATE message that called P-CSCF will carry described key send to called UE.

29. method according to claim 25 is characterized in that, the conversation message that described called AS receives is PRACK message or UPDATE message, and described called AS with the method that the key that obtains sends to called MP is:

Called AS is carried on described key in PRACK message or the UPDATE message, sends to called P-CSCF by terminating S-CSCF, and called P-CSCF gives called MP with described delivering key again.

30. method according to claim 25 is characterized in that, the conversation message that described caller AS receives is 200 message, and described caller AS with the method that the key that obtains sends caller MP is: caller AS directly sends to caller MP with the key that obtains;

Described caller AS with the method that the key that obtains sends calling UE is: caller AS is carried on described key in 200 message, sends to calling UE by terminating S-CSCF and called P-CSCF.

31. method according to claim 25 is characterized in that, the conversation message that described called AS receives is a PRACK message, and described called AS with the method that the key that obtains sends called MP is: called AS directly sends to called MP with the key that obtains;

Described called AS with the method that the key that obtains sends called UE is: called AS is carried on described key in the PRACK message, sends to called UE by terminating S-CSCF and called P-CSCF.

32. method according to claim 17 is characterized in that, described UE is a calling UE, and described network entity is the caller network entity, and described MP is caller MP; This method further comprises before the described steps A:

Calling UE sends the INVITE session to the caller network entity and sets up request message, described INVITE request message carries the media flow security ability information that calling UE provides, and the caller network entity returns 183 response messages that carry the media flow security ability information that caller MP that this side provides supports to calling UE again.

33. method according to claim 17 is characterized in that, described UE is a called UE, and described network entity is the called network entity, and described MP is called MP; This method further comprises before the described steps A:

When the called network entity receives after the INVITE session sets up request message, request message is set up in the INVITE session that carries the media flow security ability information that called MP that this side provides supports sent to called UE, called UE is returned the 183 conversational response message that the media flow security ability information that self provides is provided to the called network entity again.

34. a system that obtains media stream protection cryptographic key is characterized in that, this system comprises:

Terminal equipment UE is used to receive the key that network entity sends;

Key management functions KMF is used to generate key.

35. system according to claim 34 is characterized in that,

Described network entity is the called CSCF of caller CSCF/; Perhaps, described network entity is the called AS of caller AS/;

Described UE is calling UE/called UE;

Described MP is the called MP of caller MP/;

Described KMF is the called KMF of caller KMF/.

36. system according to claim 34 is characterized in that, described KMF is the functional module among AS or the S-CSCF.