代理多重签名的形式化模型及一个新的体制(英文)

Formal Model of Proxy Multi-Signature and a Construction

作为普通的数字签名的一种变形,代理签名允许一个代理签名人代替原始签名人进行签名.代理多重签名是代理签名的一种扩展形式,它允许两个或多个原始签名人把签名的权力委托给同一个代理签名人.自2000年以来,尽管文献中已经提出很多具体的代理多重签名方案,但是至今还未提出代理多重签名的形式化定义和安全模型.文中给出了代理多重签名的形式化定义和安全模型,并构造了一个具体的方案.在计算Co-Diffie-Hellman问题是困难的假设条件下,该方案被证明是安全的.在形式上,这个新的方案非常简单,而且最终的代理多重签名的长度是一定的,不受原始签名人个数的影响.

As a variation of ordinary digital signature scheme, a proxy signature scheme enables a proxy signer to sign messages on behalf of the original signer. Proxy multi-signature is an extension of the basic proxy signature primitive, and permit two or more entities to delegate their signing capabilities to the same other entity. Although many proxy multi-signature schemes have been proposed since 2000, to date, no precise definitions or proofs of security have been provided for them. In this paper, the authors give the syntax of proxy multi-signature schemes and formalize a notion of security for them. The authors also construct a concrete scheme which is provablysecure assuming the underlying groups are bilinear group pair and the computational Co-Diffie-Hellman problem is hard. Furthermore, the new scheme is very simple and has the property that the size of a proxy multi-signature is independent of the number of the original signers.