The Extended Differential Cryptanalysis On Three SPN Block Ciphers

Block ciphers are widely applied in the field of information security. SPN block ciphers arean important part of block ciphers. AES, ARIA and3D are the typical SPN block ciphers.Consequently, the research on SPN block ciphers is significant for academic research andpractical application.This dissertation focuses on discussing the extended differential cryptanalysis on three SPNblock ciphers–AES, ARIAand3D. The main works are as follows:1. By comparing two results of impossible differential cryptanalysis on AES, for one kindof impossible differential cryptanalysis with pre-computation, the expressions showing therelationships between the pattern of impossible differential and the complexities （including time,space and data） of attack are proposed.2. By analysing the properties of diffusion layer of ARIA, the algorithms for constructingthe4-round impossible boomerang distinguishers of ARIA are proposed, and a lot ofdistinguishers are found by the automatic search with computer. Based on them, the impossibleboomerang attack on5-round ARIA is proposed, and extended to the impossible boomerangattack on6-round ARIA-192/256. Attacking the5-round ARIA needs2^107.9 chosen plaintextsand2^107.95-round ARIAencryptions, attacking the6-round ARIA-192/256needs2^116.5 chosenplaintexts and2^137.46-roundARIAencryptions.3. By constructing the Indendent-Biclique structure, the biclique attack on full-round3Dcipher is proposed, and further extended to biclique attack on r （r≥10）-round3D cipher.Attacking the r-round3D cipher needs2³² chosen plaintexts and2⁽512+lg₂（1-485/80r）r-round3Dcipher encryptions. When r=10, the time complexity is2^510.710-round3D cipher encryptions,when r=22, the time complexity is2^511.522-round3D cipher encryptions.