In cryptography, SC2000 is a block cipher invented by a research group at Fujitsu Labs.
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.
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.
They proved that there are 268 colliding key pairs and the whole set can be found in 258 time.