The Block Cipher: SEA2 With Provable Resistance Against DC and LC Attacks.
Shih‐Hsu Chang, Fang‐Hsuan Cheng, Wen‐Hsing Hsu · 2000
This paper describes the block cipher SEA2. SEA2 is an evolutionary improvement of SEA. Modifications were made to increase the diffusion achieved per round, thus allowing for greater security and fewer rounds. Like SEA, SEA2 makes essential use of key-dependent permutations and substitutions to provide protection against differential cryptnalysis(DC) and linear cryptnalysis(LC). Our analysis shows that attacks based on DC and LC do not offer any significant improvement over a brute force attack for 4-round SEA2. The C language implementation on 4-round SEA2 could achieve a speed of about 2.9 Mbytes/sec on a 200MHZ Pentium PC, running Windows 95. Keywords: DES, encryption algorithm, block cipher, S-box, Feistel structure, security