SC2000

This article is about the encryption cipher. For the game, see SimCity 2000.

SC2000

General
Designers	Fujitsu
First published	2000
Certification	CRYPTREC
Cipher detail
Key sizes	128, 192, or 256 bits
Block sizes	128 bits
Structure	combination SPN and Feistel network
Rounds	6.5 or 7.5
Best public cryptanalysis
Differential and linear attacks exist against SC2000 reduced to 4.5 rounds

In cryptography, SC2000 is a block cipher invented by a research group at Fujitsu Labs. It was submitted to the NESSIE project, but was not selected. SC2000 is one of the cryptographic techniques recommended for Japanese government use by CRYPTREC.

The algorithm uses a key size of 128, 192, or 256 bits. It operates on blocks of 128 bits using 6.5 or 7.5 rounds of encryption. Each round consists of S-box lookups, key additions, and an unkeyed two-round Feistel network. There are 3 S-boxes: a 4×4-bit one used at the beginning of each round, and a 5×5-bit one and 6×6-bit one used in the Feistel network.

No analysis of the full SC2000 has been announced, but a reduced version of 4.5 rounds is susceptible to linear cryptanalysis, and a reduced version of 5 rounds is susceptible to differential cryptanalysis.

References

• Lars Knudsen, Håvard Raddum (7 March 2001) (PDF). A first report on Whirlpool, NUSH, SC2000, Noekeon, Two-Track-MAC and RC6. https://www.cosic.esat.kuleuven.be/nessie/reports/phase1/uibwp3-007b.pdf. Retrieved 8 February 2007. 
• Hitoshi Yanami, Takeshi Shimoyama, Orr Dunkelman (2000). "Differential and Linear Cryptanalysis of a Reduced-Round SC2000" (PDF/PostScript). Proceedings of Second Open NESSIE Workshop. http://citeseer.ist.psu.edu/yanami00differential.html. Retrieved 8 February 2007. 

• Jiqiang Lu (July 2011) (PDF). Differential Attack on Five Rounds of the SC2000 Block Cipher.. https://sites.google.com/site/jiqiang/JCST26.pdf. Retrieved 30 January 2012. 

External links

• Reference implementation and derived code