Undeniable Signature for a Group

[摘要] A new undeniable signature scheme for a group is proposed in which a group member can sign a document on behalf of the group without revealing the identity of the actual signer. The verification of the group signature can only be performed by the interaction of the verifier with the designated group prover. A trusted security mediator is used in the scheme to perform the following functions: help the members in realization of group signature, interact with verifier to verify the signature, opening of the disputed signature, and revoking the group membership. The scheme ensures that the group public key size and the group signature length are independent of the group size and, therefore, remain constant. The proposed undeniable signature scheme can be used for business applications in the situations where the signatures have high commercial values to the competitors. If any member is falsely accused of signing a document, his innocence is easily proved by group manager by tracing the original signer. The security requirements of both undeniable signatures and group signatures are satisfied by the proposed scheme.

[学科分类] 建筑学

[关键词] undeniable signatures;digital signatures;group signatures;RSA