Abstract:

In order to meet the requirements of digital signature for messages with different importance , a secret sharing-multisignature scheme without a trusted center is proposed based on the techniques of joint random secret sharing and multisignature. In this scheme , there is no trusted center , and each participant randomly selects his own secret key and publishes Lhe corresponding public key as a part of the group public key. For messages with dif-ferent importance , participants of prescriptive amount can cooperate to produce valid multisignatures without chan-ging their private and public keys. As compared with the existing schemes , the proposed scheme lowers the cost of key distribution and improves the system performance.

Key words: digital signature, secret sharing, joint random secret sharing, multisignature, trusted center