Elliptic curve cryptography is the most secure public key encryption technique.  Public key encryption means different keys for encoding and decoding. The processor based on RSD(redundant signed digit). The processor employs karatsuba of man method and Vedic multiplier for multiplication purpose. The processor can do all the arithmetic operation using an ALU(arithmetic logic unit). A comparative study between these algorithms to achieve high throughput multiplication. The implementation result based on Xilinx Spartan 3E XC3S1600E shows that the proposed algorithm can do scalar point multiplication p256.