In cryptography, CIKS-1 is a block cipher designed in 2002 by A.A. Moldovyan and N.A.
Like its predecessor, Spectr-H64, it relies heavily on permutations of bits, so is better suited to implementation in hardware than in software.
In each round the key also undergoes a transformation dependent on the data.
Kidney, Heys, and Norvell showed that round keys of low Hamming weight are relatively weak, so keys should be chosen carefully.
The same researchers have also proposed a differential cryptanalysis of CIKS-1 which uses 256 chosen plaintexts.