Abstract: Elliptic curve cryptosystems (ECC) are broadly applied in portable cryptographic devices. ECC provides the highest security strength per bit of any cryptosystem known today. However, such implementations of portable cryptographic devices of ECC are vulnerable to the widely known differential side-channel analysis (DSCA) attacks. Existing solutions reach the goal by increasing the computational costs, which prohibits the application of ECC in computation resource-restricted devices. Based on elliptic curve isomorphism mapping theory, an equal-value exchange model between elliptic curves is proposed, and then a security method that can prevent DSCA attack in ECC is designed, where almost does not increase computational costs of ECC. The accessment of security indicates that our method can resisit DSCA attacks.

Key words: elliptic curve cryptosystems (ECC), differential side-channel analysis (DSCA), simple side-channel analysis (SSCA), side-channel analysis (SCA), isomorphism mapping, point multiplicaiton