SC2000

Infobox block cipher
name = SC2000
designers = Fujitsu
publish date = 2000
certification = CRYPTREC
key size = 128, 192, or 256 bits
block size = 128 bits
structure = combination SPN and Feistel network
rounds = 6.5 or 7.5
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-round variant of 4.5 rounds is susceptible to both differential and linear cryptanalysis.

References

* cite paper
author = Lars Knudsen, Håvard Raddum
title = A first report on Whirlpool, NUSH, SC2000, Noekeon, Two-Track-MAC and RC6
date = March 7 2001
url = https://www.cosic.esat.kuleuven.be/nessie/reports/phase1/uibwp3-007b.pdf
format = PDF
accessdate = 2007-02-08
* cite conference
author = Hitoshi Yanami, Takeshi Shimoyama, Orr Dunkelman
title = Differential and Linear Cryptanalysis of a Reduced-Round SC2000
booktitle = Proceedings of Second Open NESSIE Workshop
date = 2000
url = http://citeseer.ist.psu.edu/yanami00differential.html
format = PDF/PostScript
accessdate = 2007-02-08