Method for switching three-partner key with privacy protection based on password authentication

Abstract

The present invention relates to an authenticated key exchange technique, and discloses a three-party password-based authenticated key exchange method which is provided with a privacy protection. The method comprises the following steps: an initialization step, exchanging the reserved information by two client subscribers which prepare to do key exchange; a client initialization stage, ciphering the information respectively by two client subscribers which prepare to do key exchange with the respective passwords and sharing passwords in the server and transmitting to the server together with the non-ciphered information; a server procession stage, when the server receives the request information from the client, using an oblivious transfer mechanism for processing these information and generating different returning information aiming at each one in two client subscribers, and then respectively transmitting these information to corresponding client subscriber; a client authorization step, when the client receives the returning information of the server, adopting a mechanism of normal key exchange for processing the returned information based on the password itself in order to generate the seed of the conversation key, and generating the authorization information with the seed of the conversation key for transmitting to the subscriber of the other side; and a conversation key generating step, if the authorization information from the subscriber of the other side is authorized, generating the conversation key with the seed of the conversation key. Compared with prior art, the plan not only realizes the three-party password-based authenticated key exchange, but also simultaneously and effectively protects the privacy information comprising identity and participation action of the client subscriber which participates the key exchange.

Description

technical field [0001] The invention relates to the key exchange technology based on password authentication, in particular to the security technology and privacy protection technology related to the key exchange technology based on password authentication. Background technique [0002] In Three-Party Password-based Authenticated Key Exchange ("3PAKE"), two client users share a password with the online server in advance, and then based on the password, the two users share a password on the server. Assist in mutual authentication and establish session keys. Since the password is a very short string, the amount of storage required is small and it is easy for humans to remember. It does not require additional external devices for storing keys, nor does it require public key infrastructure (PKI), so the three-party key based on password authentication Exchange protocols are widely used in practical secure communication. [0003] The three-party key exchange system based on pas...

AI Technical Summary

Problems solved by technology

This method better overcomes the disadvantage that the existing three-party key exchange scheme based on password authentication cannot effectively protect the privacy of participating users

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