Estimation of entropy rate in a fast physical random-bit generator using a chaotic semiconductor laser with intrinsic noise

Takuya Mikami, Kazutaka Kanno, Kota Aoyama, Atsushi Uchida, Tohru Ikeguchi, Takahisa Harayama, Satoshi Sunada, Ken Ichi Arai, Kazuyuki Yoshimura, Peter Davis

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27 Citations (Scopus)


We analyze the time for growth of bit entropy when generating nondeterministic bits using a chaotic semiconductor laser model. The mechanism for generating nondeterministic bits is modeled as a 1-bit sampling of the intensity of light output. Microscopic noise results in an ensemble of trajectories whose bit entropy increases with time. The time for the growth of bit entropy, called the memory time, depends on both noise strength and laser dynamics. It is shown that the average memory time decreases logarithmically with increase in noise strength. It is argued that the ratio of change in average memory time with change in logarithm of noise strength can be used to estimate the intrinsic dynamical entropy rate for this method of random bit generation. It is also shown that in this model the entropy rate corresponds to the maximum Lyapunov exponent.

Original languageEnglish
Article number016211
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Issue number1
Publication statusPublished - 2012 Jan 23


ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

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