A Design of Cryptographic Hash Function Group with Variable Output-Length Based on SHA-1

The cryptographic hash function provides the services of information security, authentication, integrity, non-reputation in a branch of information secret. A cryptographic hash function has been developed since MD4 was proposed by Rivest. In present, U.S standard of a hash function is SHA-1 with 160 bits of output length. It is difficult to be sure of a security of a hash function with 160 bits of output length. In this paper, we propose a hash function, namely SHA-V, with variable output-length based on SHA-1, HAVAL and HAS-V. The structure of SHA-V is two parallel lines, denoted as the Left-line and Right-line, consisting of 80 steps each and 3-variable 4 Boolean functions each line. The input length is 1024 bits and the output length is from 128 bits to 320 bits by 32-bit. SHA-V has the most advantage of SHA-1. That is, the message variable creates in combination with input message and step calculations. This new message variable provides the resistance against most of attacks that search the collision resistance by the fabricating of input messages. When we compare SHA-V and HAS-V in side of operation, SHA-V is 10% faster than HAS-V on a Pentium PC. Keyword Cryptographic hash functions Cryptography SHA-1, Collision resistance, MD-4, HAVAL