基于聚合签名的多方合同签署协议

An Aggregate Signature Based Multi-Party Contract Signing Protocol

利用无限制的聚合签名方案和公钥密码系统广播协议,提出了一个新的安全多方合同签署协议.合同签署协议利用广播协议实现签署者之间消息的分发,利用无限制的聚合签名方案实现签署者之间合同的签署,执行过程分为2个阶段:签署者进行消息-凭证聚合签名的交换;广播发送合同签名.如果执行过程中发生争议,签署者要求仲裁者介入,在保证其公平性的基础上结束协议.该协议满足不可伪造性、不透明性、可提取性和公平性,且随着签署者人数的增加,消息交互次数呈线性增长,效率较高.

Utilizing the unrestricted aggregate signature scheme and the public-key cryptosystem based broadcast protocol, a new multi-party contract signing protocol （MCSP） is proposed. The MCSP employes the public-key cryptosystem based broadcast protocol to distribute the messages of the signers, and employes the unrestricted aggregate signature scheme to sign the contract between the signers. The implementation of MCSP is divided into two phases：the signers exchange the aggregate signatures on the message and voucher in the first phase; then, they exchange their signatures on the contract. If a dispute occurs in the process of implementing, any signer can ask the adjudicator to settle the dispute to ensure fairness. Analysis shows that the proposed multi-party contract signing protocol satisfies the requirements of unforgeability, opacity, extractability and fairness. The proposed MCSP is with more efficience,and the interactions of messages grow linearly with the increase of the parties.