Audio Encryption Using Ameliorated ElGamal Public Key Encryption Over Finite Field

Performing encryption using ElGamal public key encryption over finite field requires imbedding of message which is represented by integers. These integers are to be imbedded to a coordinate location that satisfy the elliptic curve equation using Koblitz imbedding technique. In doing so, data expansion takes place as each integer have to be represented as a coordinate. Recommended elliptic curves have large modulo prime value, so for every small integer representation of a message, the expansion in cipher text is massive. The above factors hinders the usage of ElGamal method for large data size encryption. In the ameliorated version, every coordinates in the elliptic curve equation is applicable for performing encryption operation. The typical Koblitz imbedding technique to specific coordinates satisfying the elliptic curve equation can be avoided. Data expansion trouble is taken care by using base conversion operation with multiple audio data. Simulation results and performance comparison with other public key cryptosystem signify that the proposed method is suitable for audio encryption operation.