title: Estimation of entropy rate in a fast physical random-bit generator using a chaotic semiconductor laser with intrinsic noise.
abstract: 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.
authors.affiliation: Department of Information and Computer Sciences, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan. s10mm326@mail.saitama-u.ac.jp
authors.forename: Takuya
authors.initials: T
authors.lastname: Mikami
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kanno
authors.forename: Kota
authors.initials: K
authors.lastname: Aoyama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Uchida
authors.forename: Tohru
authors.initials: T
authors.lastname: Ikeguchi
authors.forename: Takahisa
authors.initials: T
authors.lastname: Harayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sunada
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Arai
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Peter
authors.initials: P
authors.lastname: Davis