Abstract: On the basis of the Hamming Weight leakage model, the anti algebraic side channel attack capability of a masked software DES is evaluated. The algebraic side channel attack principle is studied, and then the Hamming weight information of Sbox output of DES without protection is got based on the template attack, it is as the configurable parameters to generate conjunctive normal form of DES using script language and BAT tools, the key is retrieved by solver finally. The results show that the 56 bit DES root key can be recovered by using the Hamming weight of Sbox output from the middle 3 successive rounds, while the mask is only used to protect the first two rounds and the last two rounds of DES.