Biclique Cryptanalysis Of AES And ARIA Block Cipher

With the rapid development of computer networks technique and communication technique,society of human beings have made our passage into the information age. A message can bequickly sent from one side of the world to the other side by the information networks, which canbring great convenience to human life. The block cipher is the core element of severalsymmetric cryptosystem and an important technology to guarantee information confidentialityand integrity. It is easy to make standardization of industry and be realized rapidly by softwareand hardware. It generally be used to date encryption、authentication and key management in thefield of computer communication and information system security. For example, AdvancedEncryption Standard-AES has been widely used in commercial environment and ARIA isestablished as a Korean standard block cipher algorithm. Both algorithms have withstood allkinds of cryptographical attacks, and no efficient attack exists so far. Consequently, the study oncryptanalysis of AES and ARIA is very significant for academic research and practicalapplication.This dissertation focuses on studying of the differential trails of AES-128and the keyschedule algorithm and round function of ARIA-256. Two results are presented:1. Analyzing the differential trails of AES-128. We construct a3-round biclique from twocombined related-key differentials after round transformation. The biclique cryptanalysissuccessfully applies to full round of AES-128. Compared to former results, the cryptanalysisprovides an advantage of a factor240.2. Analyzing the key schedule procedure of ARIA-256. The number of non-differentials ofthe round key can be decreased mostly by selecting a typical master key differential. Weconstruct a2-round biclique from two combined related-key differentials after roundtransformation and firstly give a cryptanalysis result to full round of ARIA-256by combinedwith the technique of Meet-in-the-middle attack. The data complexity of the cryptanalysis is280chosen plaintexts and the computation complexity is2255.2.