Slashdot: AES: Learn All About It

“Since it was officially approved by the U.S. Government in
November of 1976, most of the world’s sensitive commercial traffic
has been secured through the use of the Data Encryption Standard
(DES). In its twenty-five year lifetime, it has become the most
widely used, most widely trusted, and most widely studied
encryption algorithm in existence. Alas, in the same way that your
Atari 2600[?] is currently sitting on the floor of your closet,
DES’ lifetime has come to an end as well. This was most
dramatically demonstrated in the three DES Challenges sponsored by
RSA Labs between January of 1997 and January of 1999, with a
DES-encrypted message eventually being broken in less than 24
hours. This challenge also witnessed the birth of a DES-specific
cracking computer, a machine widely theorized about, but never
before (publicly) built. Although variants of DES (most notably
Triple DES) are still widely used, it became clear that a new
algorithm would be needed for the next twenty-five years.”

“Thus was born the Advanced Encryption Algorithm Development
Effort. Beginning in January, 1997 (just before the RSA challenges
finally broke DES), the National Institute of Standards and
Technology announced its intent to begin the Advanced Encryption
Standard (AES) process. The initial AES workshop was held in April,
with the official call for algorithms going forth in September.
Importantly, this call specified that the algorithms submitted have
a key length of 128 bits, and be free of intellectual property
constraints. Algorithms would be accepted from domestic and
international submitters, and the resulting algorithm would be
completely public. The con test would also consider both the
hardware and the software implementation — a divergence from DES,
which was specifically designed for use in hardware. Importantly,
the hardware that the AES had to operate in could vary from the
largest supercomputer to a ROM-based smart card or other embedded
ed environment. A candidate algorithm might well be optimized for
one or the other, but had to perform at least reasonably well on
all to have a real chance of being selected. Finally, this
algorithm would be designed from the ground up to use the long key
length, and thus would be faster and more secure than Triple-DES is
at that length.”

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