一种新的广义动态密钥托管方案

A New General Dynamic Key Escrow Scheme

文章基于ElGamal公钥体制,利用单向函数不可求逆的安全特性,提出一个动态密钥托管方案,可使用于任意接入结构。与已有的其他密钥托管方案相比,它具有以下优点:(1)每个托管代理者的子密钥可以多次使用;(2)如果某个托管代理者的子密钥泄露,系统只需为它重新分配子密钥,而不必更改其他成员的子密钥;(3)系统可以很方便地增加、删除托管代理成员。该方案不但可以验证托管内容的有效性,确认欺骗者,保证了托管代理子密钥的安全性;而且提高了密钥托管的动态性和灵活性。

Based on the E1Gamal public key cryptosystem and one-way function, a dynamic key escrow scheme is presented in this paper, which can effectually identify cheaters, and be applicable to arbitrary access structures. Compared with the schemes of the same sorts, it has the following good properties. （1） The key-shadows can be reused for many times; （2） when some key agents＇ key-shadows are revealed, they can be renewed without any effect on the others; （3） the scheme can accept or fire a key agent easily. The scheme is able to verify the key-shadows of the key agents effectively, discover the failure ones, and increase flexibility of key escrow.