This paper studied side-channel attacks of ECC algorithm, and analyzed side-channel attacks weak point of the ECC algorithm. It researched point multiplication and point addition of ECC. On the basis, researched it differential power analysis attacks process of ECC, and proposed differential power analysis attack methods for unprotected and added a fixed value mask ECC algorithm. It carried out the side-channel attack experiments, analyzed the experimental results of two kinds of side-chan- nel attacks. The results show that unprotected ECC algorithm does not resist side-channel attacks. Meanw...