160 Gb/s true physical random bit generation using broad-band, high-entropy semiconductor laser chaos

Chin-Hao Tseng^1*, Ryo Funabashi², Kazutaka Kanno², Atsushi Uchida², Chia-Chien Wei³, Sheng-Kwang Hwang^1,4

¹Department of Photonics, National Cheng Kung University, Tainan, Taiwan
²Department of Information and Computer Sciences, Saitama University, Saitama, Japan
³Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan
⁴Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan

* Presenter:Chin-Hao Tseng, email:purep228@gmail.com

High-quality random bits play essential roles in many modern applications, such as Monte-Carlo simulation, stochastic modeling, and secure communication. The techniques for random bit generation can be classified into two categories. One is deterministic pseudorandom bit generation, and the other is nondeterministic physical random bit generation. Typically, pseudorandom bits are generated by software through deterministic algorithms with initial conditions. However, the bit sequences can be fully predicted if an attacker obtains the algorithms and initial conditions. Conversely, physical random bits are generated by sampling nondeterministic physical phenomena, of which randomness is more highly assured. Due to its large bandwidth and fast dynamics, semiconductor laser chaos for physical random bit generation has attracted much research interest, i.e., semiconductor lasers with optical feedback or optical injection. However, the actual entropy of chaos induced by these commonly adopted perturbation schemes is typically 1 bit/sample or less if the entropy contribution from measurement noise is excluded, limiting the generation rate of physical random bits. In this study, a novel photonic scheme is proposed for high-entropy, 2 bits/sample, chaos generation with a broad bandwidth of 33 GHz, and therefore can be used as a 2-bit physical random bit generator at a rate of 160 Gb/s.

Keywords: semiconductor lasers, broadband chaos, high-entropy, secure communication, random bit generation