一个改进的Chang加密方案

分析了Chang方案中存在的一些不安全因素，给出一个针对Chang方案的攻击方法，并在此基础上提出一个改进的Chang方案.该方案具有高强度的加密强度、容错性、不可篡改和不可重播等特点.改进方案体现了数据签名、容错技术和RSA加密的紧密结合给公钥加密带来的新思路.

An improved Chang cryptography scheme .

Digital signature and fault tolerance are two important issues in modern computer network communication. In most case, they are addressed and implemented separately. Recently, Chang proposed an integrated approach for both fault tolerance and digital signature in RSA, which can implement fault tolerance in processes of encrypting, transmission, decrypting and authentication. In this paper, we analyze some security faults which exist in Chang cryptography scheme. Then we propose an approach, which can be used to attack Chang scheme. Finally, we propose an improved Chang cryptography scheme, which provides perfect cryptography, fault tolerance, impossibility of being interpolated, impossibility of being retransmitted, and so on. The improved scheme embodies a new way of thinking for public key cryptography by integrated approach for fault tolerance and digital signature in RSA.