CLEFIA

{{Short description|Block cipher}}

{{Infobox block cipher

| name = CLEFIA

| image =

| caption =

| designers = Sony

| publish date = 2007

| derived from =

| derived to =

| certification = CRYPTREC (Candidate)

| key size = 128, 192, or 256 bits

| block size = 128 bits

| structure = Feistel network

| rounds = 18, 22, or 26

| cryptanalysis = An improbable differential attack requiring 2^126.83 chosen plaintexts breaks 13 rounds with a complexity of 2^126.83 encryptions for the key size of length 128 bits (Tezcan, 2010).{{cite book

| author = Tezcan, Cihangir

| author-link = Cihangir Tezcan

| chapter = The Improbable Differential Attack: Cryptanalysis of Reduced-Round CLEFIA

| url = http://www.springerlink.com/content/6102840421522x70/

| archive-url = https://archive.today/20130203003127/http://www.springerlink.com/content/6102840421522x70/

| url-status = dead

| archive-date = 2013-02-03

| title = Proceedings of INDOCRYPT, 2010

| series = Lecture Notes in Computer Science

| publisher = Springer-Verlag

}} Similar attacks apply for 14 and 15 rounds of CLEFIA for the key sizes 192 and 256 bits, respectively.

}}

CLEFIA is a proprietary block cipher algorithm, developed by Sony.{{cite web| title = Sony Develops "CLEFIA" - New Block Cipher Algorithm Based on State-of-the-art Design Technologies | url = http://www.sony.net/SonyInfo/News/Press/200703/07-028E/index.html | access-date = 2007-03-26}} 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 bit. 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.