Re: The Onion on Lava Lamps

From: Robert S. Thau (
Date: Wed Feb 14 2001 - 14:06:46 PST

Chris Olds writes:
> On Thu, 8 Feb 2001, Strata Rose Chalup wrote:
> > Are there lower-wattage sources of random input for cryptographic key
> > generation to fall back on?
> Is there any alternative that is as easily available that isn't patented?
> [... quoting the patent ...]
> What is claimed is:
> 1. A method for ensuring the security of a system from unauthorized
> access, comprising the steps of:
> digitizing a state of a chaotic system to form a set of binary bits;
> applying a hash function to the set of binary bits;
> obtaining a seed number from the hash function performed on the
> binary bits;
> inputting the seed number into a random number generator;
> using an output from the random number generator to form a password
> or cryptographic key, wherein the password or cryptographic key is
> used appropriately by the security system.

Hmmm... what's patented is "digitizing a state of a *chaotic* system".
Not everything unpredictable is chaos, at least in the technical
sense; in particular, chaotic systems are deterministic. So, anything
based on capturing genuine physical randomness wouldn't be covered.

In any case, there is (or ought to be) ample prior art for capturing
physical randomness... I'd be surprised if the use of radiation noise
wasn't mentioned in Kahn's "The Codebreakers".


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