动态门限多重秘密共享方案

Dynamic Threshold Multi-secret Sharing Scheme

提出一个动态的门限秘密共享方案。参与者的秘密份额由各参与者自己选择,秘密分发者无须向各参与者传送任何秘密信息,因此,他们之间不需要安全信道。当秘密更新、参与者加入或退出系统时,各参与者的份额无须更新。秘密份额的长度小于或等于秘密的长度。每个参与者只须维护一个秘密份额,就可以实现对多个秘密的共享。在秘密恢复过程中,每个参与者能够验证其他参与者是否进行了欺骗。该方案以Shamir的门限方案和RSA密码体制的安全性为基础,是一个安全、高效的方案。

This paper proposes a dynamic threshold secret sharing scheme. Each participant＇s secret shadow is selected by the participant himself and the dealer need not deliver any secret information to each participant, so a secure channel between them is unnecessary. The shadows do not need to be changed when the shared secret is renewed, old participants are deleted or new participants are added. All these shadows are shorter than or as short as the shared secret. Each participant can share many secrets with other participants by holding only one shadow, and in the recovery phase, each participant is allowed to check whether another participant provides the true information. The scheme is based on the security of Shamir＇s threshold scheme and the RSA cryptosystem. It is a computationally secure and efficient scheme.