Michael J Lieberman

US Patent:

50070878, Apr 9, 1991

Filed:

Apr 16, 1990

Appl. No.:

7/510359

Inventors:

Greg M. Bernstein - Fremont CA
Michael A. Lieberman - Berkeley CA

Assignee:

Loral Aerospace Corp. - New York NY

International Classification:

H04L 904
H03K 384

US Classification:

380 46

Abstract:

Information-theoretic notions are employed to establish the predictability of a random number generated from a circuit exhibiting chaos in order to obtain a number from a sequence of numbers with a known level of randomness and security. The method provides a measure of information loss whereby one may select the number of iterations before or between bit sampling in order to extract a secure pseudo-random number. A chaotic output is obtained by use of a sample and hold circuit coupled in a feedback loop to a variable frequency oscillator, such as a voltage controlled oscillator circuit, and operated with a positive Lyapunov exponent. A source signal generator, such as a periodic wave generator, provides a driving signal to the sample and hold circuit.