Method and device for safely consulting session key

Abstract

The invention relates to a method for safely consulting a session key, comprising the following steps of: respectively acquiring a sharing key by an access gateway and a soft switch after the access gateway successfully registers to the soft switch, and respectively storing the sharing key in the access gateway and the soft switch; distributing the session key to sessions by using the soft switch according to the request of the access gateway before the registered access gateway carries out the session each time, and encrypting the session key distributed each time by using the sharing key, and then transmitting the encrypted session key to the access gateway; decrypting the encrypted session key by using the sharing key after the access gateway receives the encrypted session key each time so that the session key is acquired. The invention also provides a device for safely consulting the session key. The invention can further ensure the security of voice conversation when ensuring the security of the key, and has easy implementation.

Description

technical field [0001] The invention relates to key processing technology, in particular to a method and device for safely negotiating a session key. Background technique [0002] In the next generation network (NGN) system, in order to reduce construction costs and facilitate user access, operators transmit VoIP signaling and media data through the Internet. Since the Internet Protocol (IP) network is an open network, its security is not high. Therefore, in order to prevent the user's phone from being eavesdropped, it is necessary to encrypt the media stream transmitted in the session to ensure the security of the voice call. The key is called a session key (SK, Session Key). [0003] At present, there are mainly two ways of negotiating a session key in the prior art: point-to-point direct negotiation and Soft Switch (SS) key distribution. [0004] figure 1 It shows an example of two access gateways (AGs) directly negotiating to obtain an SK through point-to-point negoti...

AI Technical Summary

Problems solved by technology

[0013] However, each of the above three methods has disadvantages that cannot be ignored. Among them, the disadvantages of the preset shared key method are: simple algorithm, poor security, and easy to be cracked; the disadvantages of the public key method are: PKI system is required support, and the PKI system currently used in the communication field has yet to be established, so this method is not feasible for the time being; the disadvantage of this method of DH exchange is: although the security is high, due to the complexity of the algorithm, and each call before A DH exchange is required, so the amount of calculation is too large, which seriously affects the performance of the system

Due to these reasons, the voice security guarantee in the current NGN system is difficult to achieve

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