CLEFIA

CLEFIA is a proprietary block cipher developed by Sony. Its name comes from the French word clef, meaning key. The block size is 128 bits and the key size can be 128, 192 or 256 bits. It was intended for use in digital rights management systems, and it is among the cryptographic techniques recommended as candidates for Japanese government use by the CRYPTREC revision of 2013. CLEFIA is included in the international standard ISO/IEC 29192-2:2019, which covers block ciphers for lightweight cryptography within information security, and it is also described in the Internet document RFC 6114. Published cryptanalysis of reduced-round versions includes impossible differential and improbable differential attacks reported around 2007 and 2010.