Abstract:

In the cryptographic system, the security of the key determines the security of the whole system. In order to reduce the loss of key disclosure in group signature, this paper proposes a key-isolated group signature scheme by combining the technology of key isolation with group signature. The scheme not only satisfies the security properties of group signature, such as anonymity and traceability, but also greatly reduces the harm caused by key disclosure. Key isolation technology makes the key disclosure on the current time period does not affect the signature before and after the current time period, and supports parallel message updating. The key disclosure of a single helper does not harm the initial key of the helper, thus ensuring the security of the signature. The Scheme is based on the CDH difficult problem, and the security can be proved under the random oracle model.

Key words: group signature, key isolation, parallelism, CDH