Selection of parameter ‘r’ in RC5 algorithm on the basis of prime number

With the utmost application of wireless network and internet has actuated substantial demands for information security and data concealment. However, wireless systems are more susceptible to illegitimate access and eavesdropping. RC5 has a variable parameters of word size, length of secret key and number of rounds. Ronald Rivest suggested the RC5 algorithm with 12 numbers of rounds for better encryption. In this paper, the proposed work is that if the value for the rounds in RC5 be a prime number then the security level of the cipher is more, as compared to the higher value of rounds up to next prime number. By the National Institute of Standards and Technology (NIST) suite, different tests of RC5 algorithm are performed having same data length and key but for different number of rounds and the result for prime number of round is equated with composite number of rounds and result obtained justify that RC5 for prime number of rounds provide better security level than a result drawn by a composite number of round.