Abstract
This paper introduces a collision detection methodology and an improved version of Secure Hash Algorithm (SHA-1) standard. The proposed work helps to protect weak primitives from any possible collision attack. Two designs are implemented to help protect and improve SHA-1 standard. The first design employs near collision detection approach that was proposed by Marc Stevens. The second design is the proposed work that employs two block calculation schemes. Both designs are tested and verified for examples of collided messages. The designs can detect the collision probability and produce a different hash for weak messages that are susceptible to collision attack.