The speedy tendencies in the wireless communications and personal communication methods has triggered the generation of new cryptographic algorithms. SHA-2 hash family is a new standard in the hash function category.SHA-256 is the one of hash functions of SHA-2 Family. Though SHA-2(256) is a secured Hash Function but the fear of collision attacks possible in SHA-2(256) made NIST announce a new hash function called SHA-3 or Keccak hash function.SHA-512 is one of the hash functions of the SHA-3 Family.
In this paper, both SHA-2(256) and SHA-3(512) are implemented in VHDL. The simulation and synthesis are performed in Xilinx ISE 13.2.The area consumed by both the hash algorithms is compared. Message Preparation, Message Expansion, Round logic and Round Addition are major steps performed in SHA-2(256). The basic SHA-3 presented here converts 128 bits input into 512 bits within the intermediate stage using one C-box. The main steps performed by C-Box are Theta, Rho, Pi, Chi and Iota. SHA-3(512) is more secure hash function but it utilizes more area compared to SHA-2(256).
Keywords: Cryptography, Hash Function, Theta, Rho, Pi, Chi, Iota.