Abstract: In order to make up the safety assessment of S-boxes, which was traditionally tested by mathematical methods, correlation power analysis and template attack were used on different S-boxes of DES, AES and Serpent. The simulations were put forth by MATLAB to obtain the success rates. The S-box of Serpent was the strongest against both the correlation power analysis and template attack. In correlation power analysis, Serpent needed 206 power traces, while AES and DES needed only 112 and 160 respectively. In addition, AES was stronger than DES against template attack. The results showed that the low-wide S-box was stronger than the high-wide S-box with the same total number of bits in one round.

Key words: correlation power analysis, S-box, block cipher, template attack, power analysis attack, power trace