DEAL

DEAL is a Chiffrement per block derived from OF the and proposed by Lars Knudsen in 1997. Coding will be candidate for AES (sent by Richard Outerbridge).

DEAL is based on a Réseau of Feistel, they are in fact a coding which employs DES. He treats a block of 128 bits and called upon keys 128,192 or 256 bits. The number of revolutions depends on the key: 6 per 128 or 192 bits, 8 per 256 bits. Enough slow, it is comparable with 3DES and after cryptanalyse, it proves weaker than the other candidates of AES.

Knudsen proposed itself an attack which decreases reliability by limiting the theoretical robustness of coding is equivalent to a coding of 122 bits in the case of 6 turns (either a theoretical “loss” of 70 bits compared to the key of 192 bits). As DEAL was already likely to be tackled by a meeting in the middle of share its design, this terminal was before of 168 bits (224 bits for the key of 256 bits). The attack of Knudsen requires 270 plaintexts for a complexity of 2121 codings. The generation of the intermediate keys (Key schedule) was cryptanalysée by Bruce Schneier and John Kelsey. An attack is possible on only 5 rounds instead of the 6 envisaged. In conclusion, DEAL present of serious vulnerabilities compared to other candidates AES but it at the advantage of being able to be implemented on material at the origin envisaged for because it uses most of the concepts of this last.

DEAL evolved to other codings like DEALkx-120 and DEALkx-128.

External bonds

  • original Rapport on DEAL
  • Présentation for AES (pdf)
  • How to make Of-based the smartcards made for the 21st century, Stefan Lucks

References

  • John Kelsey, Bruce Schneier: Key-schedule Cryptanalysis off DEAL. Selected Areas in Cryptography 1999:118 - 134
  • Stefan Lucks: One Security off the 128-Bit Block Cipher DEAL. Fast Software Encryption 1999:60 - 70

Random links:Leon Rippy | Nafeez Mosaddeq Ahmed | Crater of New Quebec (Pingualuit) | Aero Cheer Cheer 700 | Nikkatsu | Tétrachlorure_de_carbone