Proposed 256 bits RC5 Encryption Algorithm Using Type-3 Feistel Network

Abstract

Proposed 256 bits RC5 is an improvement to RC5, designed to meetthe requirements of increased security and better performance. Proposed256 bits RC5 algorithm makes use of data dependent rotations. One newfeature of proposed 256 bits RC5 algorithm is modified its design to usefour 64-bit registers rather than two 32-bit registers. The proposal 256 bitsRC5 algorithm using Type-3 Feistel network which is iterated simplefunction 20 times. An Avalanche Effect of RC5 is about 31.372 if wechange the same amount of information in key for 256 bits RC5 then theAvalanche Effect is about 142.909. The proposed algorithm is resistant tomatching and a dictionary attack which is increased the security of theprevious RC5 algorithm by using block size of 256 bits instead of 64 bits.