NOEKEON

Noekeon
General
Designers	Joan Daemen, Michaël Peeters, Gilles Van Assche, Vincent Rijmen
First published	2000-09
Derived from	3-Way, BaseKing
Cipher detail
Key sizes	128 bits
Block sizes	128 bits
Rounds	16

NOEKEON /ˈnuːki.ɒn/ is a family of two block ciphers designed by Joan Daemen, Michaël Peeters, Gilles Van Assche and Vincent Rijmen and submitted to the NESSIE project in September 2000. The two ciphers are "direct mode" NOEKEON, to be used for maximum efficiency where related-key attacks are not possible, and "indirect mode" NOEKEON where they are.

NOEKEON has a 128-bit block and key size. Each round of NOEKEON employs a sequence of self-inverse transformations which can be implemented easily in hardware or software, even where differential power analysis is a concern. It is designed according to a variant of the wide-trail strategy.

Cryptanalysis by Lars Knudsen and Håvard Raddum in April 2001 showed that "indirect mode" NOEKEON was still vulnerable to certain peculiar kinds of related-key cryptanalysis, and showed weaknesses in NOEKEON-variant ciphers which cast doubt on the design strategy behind NOEKEON and thus on its security. As a result it was not a NESSIE selected algorithm.

The authors of NOEKEON contend ("On NOEKEON, no!") that the related-key attacks required to break "indirect mode" NOEKEON are not a practical concern, and that it is as a result of deliberate design that NOEKEON is not vulnerable to the attacks that break the variant ciphers; they assert that NOEKEON is still a good and useful cipher.

External links

The NOEKEON Page
Lars Knudsen and Håvard Raddum On NOEKEON

Block ciphers (security summary)

Common algorithms	AES (Implementations) Blowfish DES (Internal Mechanics, Triple DES) Serpent Twofish

Less common algorithms	Camellia CAST-128 IDEA RC2 RC5 SEED Skipjack TEA XTEA

Other algorithms	3-Way Akelarre Anubis ARIA BaseKing BassOmatic BATON BEAR and LION CAST-256 Chiasmus CIKS-1 CIPHERUNICORN-A CIPHERUNICORN-E CLEFIA CMEA Cobra COCONUT98 Crab Cryptomeria/C2 CRYPTON CS-Cipher DEAL DES-X DFC E2 FEAL FEA-M FROG G-DES GOST Grand Cru Hasty Pudding cipher Hierocrypt ICE IDEA NXT Intel Cascade Cipher Iraqi KASUMI KeeLoq KHAZAD Khufu and Khafre KN-Cipher Ladder-DES Libelle LOKI (97, 89/91) Lucifer M6 M8 MacGuffin Madryga MAGENTA MARS Mercy MESH MISTY1 MMB MULTI2 MultiSwap New Data Seal NewDES Nimbus NOEKEON NUSH PRESENT Q RC6 REDOC Red Pike S-1 SAFER SAVILLE SC2000 SHACAL SHARK Simon SMS4 Speck Spectr-H64 Square SXAL/MBAL Threefish Treyfer UES Xenon xmx XXTEA Zodiac

Design	Feistel network Key schedule Lai-Massey scheme Product cipher S-box P-box SPN Avalanche effect Block size Key size Key whitening (Whitening transformation)

Attack (cryptanalysis)	Brute-force (EFF DES cracker) MITM (Biclique attack, 3-Subset MITM attack) Linear (Piling-up lemma) Differential (Impossible Truncated Higher-order) Differential-linear Integral/Square Boomerang Mod n Related-key Slide Rotational Timing XSL Interpolation Partitioning Davies' Rebound Weak key Tau Chi-square Time/memory/data tradeoff

Standardization	AES process CRYPTREC NESSIE

Utilization	Initialization vector Mode of operation Padding

Cryptography

History of cryptography Cryptanalysis Cryptography portal Outline of cryptography

Symmetric-key algorithm Block cipher Stream cipher Public-key cryptography Cryptographic hash function Message authentication code Random numbers Steganography