An improved sliding window algorithm for ECC multiplication

Elliptic curve cryptosystem (ECC) is broadly applied to authentication, certification, key distribution and message encryption in recent years, since its quite benefit in stronger safety and computational efficiency than RSA, a primary public key system used for all most twenty years. How to improve the computational efficiency of ECC is a hot topic, the focus of this issue is at the scalar multiplication, a main computation in ECC. This paper presents a variable window mechanism method of combining NAF and variable-length sliding window to scale down the complexity of computations of point multiplication of ECC. The presented algorithm improves the efficiency by reducing the point multiplication computation and point addition computation totally. Both theoretical analysis and test result show that computation efficiency of encryption based on ECC improves well.