Enhance SHA-1 for Building Secure System to Transfer Voice Files

Abstract

This paper introduces a proposed secure system to transfer the voice files as a hashed and encrypted data over communication channels with two experiments. Two experiments are suggested; using SHA-1 in first one and modified SHA-1 in the second, and for the two experiments RSA and AES are used for encryption. Modified of SHA-1 is suggested since there is a theoretical algorithms can break and penetrate it. The proposal trends to modify SHA-1 with two suggestions; which are proofed by experimental works. These suggestions are; (i) increase the number of round from 80 to 83 where the three additional rounds are injected into the first stage to be 23 rounds instead of 20. (ii) inject each round with randomize operation with each round; which is an expansion procedure used in DES to extend length from 160-240 bits, then followed by DES S-Boxes pruning procedure to preserve the digest length by reduce the length from 240-160 bits. Both of increasing number of rounds and the injection will increase SHA-1 security and complexity to overcome the flaws, which make it theoretical breakable. Keywords: AES, SHA-1, DES S-boxes, Voice Files