FPGA implementation of stream cipher using Toeplitz Hash function

Hardware efficient stream ciphers and hash functions are widely used in cryptographic applications. The one-wayness and low hardware complexity of hash function make it a good candidate for authentication operation of crypto-systems. On the other hand, stream ciphers are being widely used in the domain of cryptology. Generally, these stream ciphers use static key stream for the crypto process. In this work, we propose a hash function based key generator and integrate the hash function based key generation with the RC4 stream cipher block so as to provide dynamic key to the RC4´s encryption system thus realizing a robust security hardware prototype. The proposed method is designed for 5-bit hash key and stream cipher using Verilog HDL and simulated using Xilinx ISE 14.2 simulator. Further the design implementation has been done on the commercially available Xilinx Spartan 3E fg320-4 FPGA device. The excellence of the generated random key value by our proposed method is validated using the statistical tests proposed by National Institute of Standard and Technology (NIST).