FAPKC签名和加密混合使用的安全性分析

在实际的应用密码系统中有一个重要的原则：密钥只能有单一的用途，它仅用于加密或仅用于签名.但是Haber和Pinkas指出，在许多情况下，在两个不同的密码系统中(比如一个公钥加密系统和一个公钥签名系统)同时使用有关联关系的密钥实际上并不会损害系统的安全性.有限自动机公开钥密码体制既可用来加密，也可用来签名，因而是一个混合密码系统.对FAPKC加密和签名混合使用的安全性进行了分析，证明了混合使用FAPKC不损害密码体制的安全性.

The Combined Use of FAPKC Without Compromising the Security of the Cryptosystem

It is a maxim of sound computer security practice that a cryptographic key should have only a single use. But S.Haber and B. Pinkas show that in many cases, the simultaneous use of related keys for two cryptosystems, e.g. for a public key encryption system and for a public key signature system, does not compromise their security. Finite automata public key cryptosystem can be used for both encryption algorithm and signature algorithm, it is a combining cryptosystem. In this paper, it is proved that the combined use of finite automata public key cryptosystem does not compromise the security of the cryptosystem.