Enhanced Strand Space for secure protocol analysis

Strand space inherits the merit of algebra method, which can prove the security of protocol more precisely for it overcomes the shortcoming of inconvenience. But because of shortage of primitives it can´t describe some protocols as IKE, let alone verification. We made improvement to the original strand space by adding the description of hash function and some definitions with lemmas. So we can use the intensive model to analyze the protocols using hash function. At last, we analyze one IKE subprotocol protocol.