title: Noise robustness of unpredictability in a chaotic laser system: toward reliable physical random bit generation.
abstract: We introduce a concept of noise robustness in dynamical systems with noise and argue that this concept is essential to guarantee the reliability of physical random bit generators (RBGs). As an example of promising physical RBGs we consider a chaotic laser system and show that it has the property of noise robustness with respect to changes in the temporal correlation of the noise source. Moreover, employing a simple model of tangent space dynamics, we give a theoretical interpretation of the numerical results and in particular show that the Lyapunov exponent determines a theoretical boundary of a noise-robust region in parameter space. These theoretical results are expected to be significant not only for chaotic lasers, but also for a broad class of chaotic dynamical systems with correlated noise.
authors.affiliation: NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya Atsugi-shi, Kanagawa 243-0198, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Inubushi
authors.affiliation: NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya Atsugi-shi, Kanagawa 243-0198, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Telecognix Corporation, 58-13 Shimooji-cho, Yoshida, Sakyo-ku, Kyoto 606-8314, Japan.
authors.forename: Peter
authors.initials: P
authors.lastname: Davis