Quantum random number generators promise perfectly unpredictable random numbers. A popular approach to quantum random number generation is homodyne measurements of the vacuum state, the ground state of the electro-magnetic field. Here we experimentally implement such a quantum random number generator, and derive a security proof that considers quantum side-information instead of classical side-information only. Based on the assumptions of Gaussianity and stationarity of noise processes, our security analysis furthermore includes correlations between consecutive measurement outcomes due to finite detection bandwidth, as well as analog-to-digital converter imperfections. We characterize our experimental realization by bounding measured parameters of the stochastic model determining the min-entropy of the system’s measurement outcomes, and we demonstrate a real-time generation rate of 2.9 Gbit/s. Our generator follows a trusted, device-dependent, approach. By treating side-information quantum mechanically an important restriction on adversaries is removed, which usually was reserved to semi-device-independent and device-independent schemes.
Bibliographical noteFunding Information:
The authors acknowledge support from the Innovation Fund Denmark through the Quantum Innovation Center, Qubiz. T.G., A.K., D.S.N., N.J., and U.L.A. acknowledge support from the Danish National Research Foundation, Center for Macroscopic Quantum States (bigQ, DNRF142). T.G., N.J., S.P., and U.L.A. acknowledge the EU project CiViQ (grant agreement no. 820466). C.L. was also supported by the EPSRC Quantum Communications Hub, grant no. EP/M013472/1. The authors thank Alberto Nannarelli for valuable discussions.
© 2021, The Author(s).