Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography

Area of Science:

• Cryptography and secure communications
• Applied physics
• Information theory

Background:

• Random bit generators (RBGs) are crucial for cryptography and secure communications, demanding high-speed, unpredictable bit strings.
• Deterministic pseudo-random number generators have limited unpredictability.
• Physical RBGs using chaotic lasers offer high generation rates (Gbit/s), but their secure synchronization is an open challenge.

Purpose of the Study:

• To propose and validate a method for secure synchronization of high-rate physical RBGs.
• To assess the security of this synchronization method against computational eavesdroppers.
• To extend the method for synchronizing a network of three RBGs.

Main Methods:

• Utilizing mutually coupled chaotic semiconductor lasers for RBG implementation.
• Employing information-theoretic analysis to evaluate security.
• Demonstrating synchronization of two and a network of three RBGs.

Main Results:

• Successful synchronization of two fast physical RBGs based on mutually coupled chaotic lasers.
• Information-theoretic security demonstrated against a powerful eavesdropper with noiseless amplification capabilities.
• The method is adaptable for synchronizing a small network of three RBGs.

Conclusions:

• The proposed method enables secure synchronization of high-rate chaotic laser-based RBGs.
• This approach offers a viable solution for secure key-exchange protocols in demanding communication scenarios.
• The findings advance the practical application of physical random bit generation in secure systems.