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Journal of Inforamtion Science and Engineering, Vol.16 No.6, pp.813-834 (November 2000)

The Blobk Cipher: SEA2 With Provable Resistance
Against DC and LC Attacks

Shih-Hsu Chang, Fang-Hsuan Cheng and Wen-Hsing Hsu
Department of Computer Science and Information Engineering
Da-Yeh University
Changhwa, Taiwan 515, R.O.C.
*Department of Computer Science
Chung-Hua University
Hsinchu, Taiwan 300, R.O.C.
+Department of Electrical Engineering
National Tsing Hua University
Hinchu, Taiwan 300, R.O.C.
++Institute of Information Science
Academia Sinica
Taipei, Taiwan 115, R.O.C.

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

Full Text () Retrieve PDF document (200011_02.pdf)

Received March 6, 1999; accepted August 4, 1999.
Communicated by Chi Sung Laih