-----BEGIN PGP SIGNED MESSAGE----- In article <ad63bf5600021004e133@[205.199.118.202]>, tcmay@got.net (Timothy C. May) wrote:
Steven Wolfram had some speculations about using fractal or cellular automata-based systems for a new kind of cipher. His paper is in one of his books ("Theory and Application of Cellular Automata"), but it doesn't really get beyond just speculating. And, I recall that someone proved several years ago that Wolfram's CA-based encryption scheme was formally equivalent to a linear congruential generator.
I think I included a few paragraphs on this topic in my Cyphernomicon.
Schneier has a few words to say about cellular automata in the first edition of APPLIED CRYPTOGRAPHY (I don't have the 2nd, shame on me). Howard Gutowitz published and patented in 1992 a symmetric block cipher algorithm, based on cellular automata, called CA-1.1 . There are a couple of CA-based hash algorithms. CA-based PRNGs have been shown to be isomorphic to linear feedback shift register RNGs (not linear congruential generators, despite what Tim says) and so are subject to the same security woes as LFSRs. - -- Alan Bostick | I'm laughing with, not laughing at. mailto:abostick@netcom.com | The question is, laughing with WHAT? news:alt.grelb | James "Kibo" Parry <kibo@world.std.com> http://www.alumni.caltech.edu/~abostick -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQB1AwUBMUIZgeVevBgtmhnpAQG3YQL+PUxnW30lCOTfqN5JmrB6RSWD0c/pZbNU 0qijNq0Ka0i+yDBVkbgR8Gdd+vyS6gZKzpbWQxuvv1Xrqg7aeuh/0nEnTLSclpfB AJShGFEVN1+XSs7zLWIHdQ0CdM/ZSuKL =JuFk -----END PGP SIGNATURE-----