Trade-off between length of the Hash code and performance of hybrid routing protocols in MANETs

Message authentication is a mechanism to verity the integrity of a message and it can be achieved using Message Authentication code (MAC) also called as keyed hash function. An ideal Hash algorithm will require a cryptanalytic effort greater than or equal to the brut-force effort. In the recent time, there have been enough efforts in developing cryptanalytic attacks on Hash algorithms. The hash algorithms contain a compression function which takes n-bit input from the chaining variable taken from previous step, b-bit block from the input message and produce an n-bit output. The initial value of chaining variable is specified as part of the algorithm and the final value of the chaining variable becomes hash value or message digest which is attached the message being transmitted. In this paper, we have implemented HMAC-SHA256 and HMAC-SHA512 algorithms for the Data Integrity of the information being sent using a hybrid routing algorithm for Mobile Ad hoc Networks (MANETs). The hybrid routing algorithm which we have taken here is Zone Routing Protocol (ZRP) and the tool used for simulation was NS2.33. The metrics that we have considered to analyze the performance of the protocol were Throughput, Packet delivery fraction and End-to-End Delay.