20 Gbps real-time source-independent quantum random number generator based on a silicon photonic chip

Quantum random number generator (QRNG) allows for the production of truly unpredictable random numbers, thanks to the inherent randomness available in quantum mechanics. However, its practical implementation is facing several challenges, including the practical security loophole, high-speed real-time randomness extraction, and large-scale production. In this work, we address these challenges with a chip-based, source-independent quantum random number generator achieving 20 Gbps real-time generation rate. It ensures the practical security through a source-independent security framework and the modeling of measurement devices. A bandwidth exceeding 2 GHz and a clearance reaching 10 dB is achieved by a silicon-based homodyne detector. Analog-to-digital conversion and randomness extraction are integrated on a single data collection and processing board, where the optimized parallel randomness extraction algorithm on a field programmable gate array achieves a throughput up to 28 Gbps. The results promise a high-speed and practically secure quantum random number generation on a chip, paving the way for its large-scale deployments and widespread applications.