CSCI 360 Slide deck 7

AES = ADvanced Encryption Standard

The demise of DES

By the late 1990s the 56 bit key of DES was getting very problematic.

In 1998 the EFF spent $250,000 to build "Deep Crack" (https://en.wikipedia.org/wiki/EFF_DES_cracker)

This is what happens when engineers choose names.

Deep Crack was able to find a DES key in 56 hours.

A new hope

In 1997 NIST called for proposals for a new Advanced Encryption Standard.

In three rounds NIST and the international scientific community discussed the advantages and disadvantages of the submitted ciphers.

Requirements:

  1. Block cipher with 128 bit block size
  2. Three key length options: 128, 192 and 256.
  3. Good security
  4. Efficiency in software and hardware

The contest

There were 15 ciphers submitted. Five were finalists:

  1. Mars by IBM
  2. RC6 by RSA Labs
  3. Rijndael by Joan Daemen and Vincent Rijmen
  4. Serpent by Ross Anderson, Eli Biham, and Lars Knudsen
  5. Twofish by Bruce Schneier, John Kelsey, Doug Whiting, David Wagner, Chris Happ and Niels Ferguson.

The winner: Rijndael

rijndael

AES $\approx$ Rijendael, official on 11/26/2001

Government use