Re: IBM press release - encryption and authentication

[Bram Cohen]

On Sun, 10 Dec 2000, Rodney Thayer wrote:

> P.s, when he spoke at Stanford I asked about patents and he said
> it was patented, and he said NIST is trying to get them to put it
> in the public domain.

There are slides for it online at

http://csrc.nist.gov/encryption/aes/modes/slides-jutla/index.htm

it's not hard to figure it out just from the slides - there are actually
two methods given, one which requires an extra lg(n) encryptions and one
which requires two extra encryptions but has a bunch of modular
arithmetic. Rijndael is so fast I suspect the second one might not prove
all that useful.

It really does, as advertized, offer MAC for almost no overhead, and
parallelization for free. It would be a shame for these modes to not get
used because of stupid patent bullshit.

-Bram Cohen

(who thinks doing the xors as a gray code instead of binary countup was a
nice touch.)