This document verified A(0) protocol and Needham-Schroeder public key protocol with the reversing verification method, with the reasoning process and attacking trace being given and the protocol problem being located.

• 本文使用这种反向验证方法验证了A(0)协议和Needham-Schroeder公开密钥协议，给出了推导过程以及攻击路径，并且定位了协议所存在的问题。