Method and system for realizing safe bifurcation call session in IP multimedia subsystem

Abstract

The invention provides a method and a system for realizing a safe bifurcation call session in an IP multimedia system. In the invention, based on Otway Rees key agreement protocol, a key agreement system is provided and is enabled to realize the safe bifurcation call session in the IP multimedia subsystem (IMS). When a called party receives a call, a slave calling key management server (KMS) acquires a media root key K used for deriving media keys; then based on a random number and the media root key K which are derived by each called party, each called party and each calling party can derive a media key respectively by utilizing a media key deviation function (KDF). The media key of each called party is unique and cannot be learned by other terminals, thereby realizing media safety of the bifurcation call session. The invention has simple logic, reduces computing and processing pressure of the calling party, interacts less with a KMS signaling, relieves storage and computation requirements for the KMS, and excellently provides the safety protection for ensuring the bifurcation call session for the IMS.

Description

technical field [0001] The invention relates to network communication security technology, in particular to a method and a system for realizing safe bifurcation call session based on the Otway-Rees key negotiation protocol in an IP multimedia subsystem (IMS). Background technique [0002] In the Session Initiation Protocol (SIP) system, forking call session (Forking call) is a very useful service, which enables multiple terminals of the called party to be called at the same time, thus improving the probability of call connection . IMS uses the SIP protocol as the control protocol for various IP multimedia services. In the technical specifications of IMS media security, forking call sessions have been listed as a very important user scenario, and corresponding security requirements have also been proposed. [0003] Figure 1a and Figure 1b They are schematic diagrams of two scenarios of the existing forked call session respectively. in, Figure 1a It is the case that the ...

AI Technical Summary

Problems solved by technology

However, this method does not provide a new key agreement mechanism, but only reduces the requirements for the processing capacity of the call terminal. Moreover, since the key agreement has not been completed when the answer is made, the media stream at this time cannot be protected by encryption, which introduces another A new delay problem for the calling terminal and the answering terminal to negotiate the media key after answering

Therefore, this method of adding a delay mechanism cannot realize the key negotiation on the one hand, and on the other hand, it does not really solve the problems of large processing capacity and high computational requirements.

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