Confounding method of encrypted group signatures

Abstract

The invention relates to a confounding method of encrypted group signatures, thereby protecting signature private keys of members in a group. The method comprises the following steps that: (1), a group master constructs a signature group and a group parameter sequence pub, a main private key MK, a tracking private key TK are obtained according to a setup algorithm; (2), an information receiver obtains a respective encrypted public key PKe and decrypted private key SKe based on an EKGen algorithm according to the group parameter sequence pub: (3), according to the group parameter sequence pub, the main private key MK, and IDs of the members in the group, the group master obtains signature tracking information sID and signature private keys KID corresponding to the respective IDs of the members in the group by using an Enroll algorithm, and the signature private keys KID are sent to corresponding members in the group; (4) according to a confounding algorithm Obf, confounding processing is carried out on an initial encryption group signature algorithm EGS of the members in the group and the signature private keys KID of the members in the group, thereby obtaining an encryption group signature algorithm Rpub,z,PKe; and (5), according to the encryption group signature algorithm Rpub,z,PKe, information signature encryption is carried out a to-be-sent message M to generate an encrypted ciphertext C and then the encrypted ciphertext C is sent to the information receiver. Compared with the prior art, the confounding method has advantages of function of private key protection and good secret keeping effect and the like.

Description

technical field [0001] The invention relates to the fields of cryptography, group signatures and confusion theory, in particular to a method for confusing encryption group signatures. Background technique [0002] Group signature is a special digital signature designed for a group of members, originally proposed by Cham and Heyst. In a group signature, there is a group manager and many members. Each group has a group public key for authentication. Each group member has an independent private key to generate a group signature, and its signature can be detected by the group public key. Group managers have a master key. Assuming a signature, the group administrator can use the master key to know which group member generated the signature. This is traceability. In addition, other group members without the master key cannot know which group member generated the signature, which is called anonymity. In fact, group signatures have the following four properties: 1) only group ...

AI Technical Summary

Problems solved by technology

A typical white-box attack environment is, for example: a computer that has been compromised and obtained administrator privileges, a mobile agent running on a malicious host, a stolen tablet or smart phone, etc. (at this time, for professional hackers , breaking access passwords or graphic passwords is not difficult), in addition, the SSL Heartbleed vulnerability exposed in 2014 can allow attackers to remotely obtain certain memory segments on the server, and if the signature key is stored in it, the consequences are equally serious

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