Correlation Analysis Of AES Based On Power Trace Preprocessing

As a new cryptanalysis method,side-channel-analysis has been increasingly concerned by related scholars.Unlike traditional cryptanalysis,side-channel-analysis does not require researchers’ deep mathematical skills.It uses the side channel information,such as the time differences,power consumption or electromagnetic radiation,Cache leak,etc.,leaking from cryptographic algorithm.By analyzing the correlation between the side channel information and key or intermediate computing operations,we can get the key of cryptographic algorithm,then break the cryptographic system.Due to the principle of simple,less experimental constraints and so on factors,power analysis make it a basic analysis method of side-channel-analysis.By analyzing the correlation between the power consumption generated by the cryptographic algorithm and the sub-key information in the intermediate calculation process,we can calculates the correlation coefficient between the power consumption and the key,using theory of correlation calculation in statistics.And then we can get the key of the cryptographic algorithm.In this dissertation,we propose the energy trace preprocessing method to improve the correlation power analysis model.We take the AES algorithm as the research object,and do some preprocessing with power trace to improve the correlation power analysis model.Specifically from the following three aspects to achieve:1.A simple and easy understanding feature extraction scheme based on difference is proposed.Because the power consumption generated by encryption with different keys is slightly different,we can get the difference trajectories after executing encryption many times.In the difference trajectories,the index of larger correlation coefficient is the feature points we want.2.Improves the former using phase replacement to align the power trace in the frequency domain.By using the time-shift property in Fourier transform,the method has been improved,which makes the alignment preprocessing method easier and more applicable.3.First introduce the concept of wavelet analysis to the side-channel-analysis’power trace preprocessing.Due to the limitation of the Fourier transform in the digital filter to deal with the non-stationary signal,the concept of wavelet analysis is introduced,and then use it to separate the signal from noise.Through the above three preprocessing scheme,after the collected power trace is preprocessed,and then through the correlation power analysis,we can get the AES key faster with less time and space resources,and the success rate has also been improved.