Abstract: This paper presents the design and simulation of a new encryption scheme for wireless communication which is simple in implementation as well as highly resistant against the attack. It utilizes the selective repeat ARQ to produce the retransmission sequence. The correct production of retransmission sequence relies on the fact that error detection should be very precise. For that purpose an error detection scheme is as also included. Then the retransmission key is hashed by using SHA-512 to produce an unpredictable key. Then the key is XOR-ed with the original message to produce the cipher text.

Keywords: Selective Repeat ARQ, SHA-512, Retransmission sequence, MATLAB GUI, CRC-32