Research On Power Analysis Based On The Diffusion Layer Of The Blockcipher

As the core technology of information security,the security ofcryptographic algorithms is usually determined by the cost ofmathematical analysis. However,in practical applications, cryptographicalgorithms are usually implemented through a variety of cryptographicchips. The security is not only associated with the cryptographicalgorithms, but also with the implementation of software and hardwaredesign. Side-channel Attack, as a very important branch of cryptoengineering, exploits side-channel information to reveal secret parameters.Among all of side-channel attacks, power analysis attack is mostdangerous and easily performed. attacker obtains the key information ofcrypto equipment only by analyzing the power generated during theoperation of the equipment.As an important part of block cipher, diffusion layer plays a role toensure that one bit in plaintext can affect multiple bits in ciphertext, whilefor the diffusion layer of block cipher algorithm,it is difficult to get thekey to algorithm using the conventional method of power analysis attack.This paper mainly explores the method of power analysis attack against thediffusion layer of block cipher. Specifically, the research mainly includestwo aspects: firstly, a new method of attack is proposed for the diffusionlayer of SMS4algorithm, i.e. chosen-plaintext attack, which takes fulladvantage of the structure of SMS4and overcomes the problem of highdiffusion; secondly, Hamming distance model and bit model are used toattack against simulation curves. Experimental results show that thismethod is effective and Hamming distance model requires less curves. Moreover, for the diffusion layer of AES algorithm, the correspondencebetween input bytes and output bytes after mixcolumn is used to propose amethod of amortized analysis. Simulation results show that this method iseffective, but requires more power consumption curves. Finally, based onthe structure of AES, the method of chosen-plaintext attack is successfullytransplanted toAES algorithm.