Message Authentication Method Based on Hash Function

Based on the requirements of message authentication code (MAC) in current network communication, this paper introduces the cryptographic secure properties of a Hash function, and analyses its applications in message authentication and the main attacks against a Hash function. It presents a new message authentication method based on a hash function, the pseudo-message authentication code (PMAC). The proposed method constructs a MAC by an existing Hash function, and doesn’t change the inner structure of this Hash function. The proposed method, which doesn’t apply any existing encryption arithmetic, can provide message confidentiality as well as authentication by only a secret key. This paper gives a basic security analysis of PMAC.