CLEFIA

CLEFIA is a proprietary block cipher algorithm, developed by Sony.^[2] Its name is derived from the French word clef, meaning "key". The block size is 128-bits, and the key size can be 128-bit, 192-bit or 256-bits. It is intended to be used in DRM systems. It is among the cryptographic techniques recommended candidate for Japanese government use by CRYPTREC revision in 2013.

CLEFIA

General
Designers	Sony
First published	2007
Certification	CRYPTREC (Candidate)
Cipher detail
Key sizes	128, 192, or 256 bits
Block sizes	128 bits
Structure	Feistel network
Rounds	18, 22, or 26
Best public cryptanalysis
An improbable differential attack requiring 2126.83 chosen plaintexts breaks 13 rounds with a complexity of 2126.83 encryptions for the key size of length 128 bits (Tezcan, 2010).[1] Similar attacks apply for 14 and 15 rounds of CLEFIA for the key sizes 192 and 256 bits, respectively.

Standardization

CLEFIA is included in the following standards.

• ISO/IEC 29192-2:2019, Information security - Lightweight cryptography - Part 2: Block ciphers^[3]