Abstract: Recently, as the security problem for wireless internet environment has emerged, Elliptic Curve Crypto system (ECC) has emerged as a next generation cryptosystem that provides a solution to this problem. In this study, Simple Power Analysis (SPA) attack method which is one of the subchannel attacks is called public key-based password required for information security and authentication of smart home appliances included in smart grid system we design and develop a elliptic curve cryptosystem algorithm that can perform a given task independently.