The invention discloses an application method of a
Hamming distance model on SM4 cryptographic
algorithm lateral information channel
energy analysis and based on
S box input. The application method is characterized in that the
Hamming distance model is established by selecting an
S box or a
round function as an attacking point in the process that the SM4 cryptographic
algorithm lateral information channel
energy analysis is carried out, the input of the
S box is used as an initial state v1 of the
Hamming distance model, the output of the S box is used as subsequent state v2 of the Hamming distance (HD (v1, v2)) model when the S box is attacked, and the output / input of the
round function is used as the subsequent state v2 of the Hamming distance (HD (v1, v2)) model when the
round function is attacked. The method can be applied to CPA / DPA lateral information channel
energy analysis of the SM4 cryptographic
algorithm. Correlation between a correct guess secret key and
energy information is improved, and validity and success rate of the analysis are enhanced.