关键词: 强前向安全性, 门限签名, 中国剩余定理, 秘密共享

Abstract:

The traditional cryptosystem is based on the security of private key. However if the private key is leaked, the user information may be exposed. Aiming at the problem, a strong forward-secure dynamic threshold signature scheme is proposed. The scheme is based on the Chinese remainder theorem without a dealer. The signature is generated through the cooperation of members, which solve the problem of authoritative fraud introduced by the dealer. The private keys are updated periodically to handle the threat of leakage. The new scheme allows members’ join and exit. Security analysis shows that both of the existing signatures and future signatures will not be affected by the leakage of the corresponding private keys, which means the new scheme has both the forward security and the backward security, and is therefore strong forward-secure. The efficiency analysis shows that the scheme is more efficient compared with the well-known existing schemes in the literature.

Key words: strong forward security, threshold signature, Chinese remainder theorem, secret sharing