Reliable randomness is a core ingredient in algorithms and applications ranging from numerical simulations to statistical sampling and cryptography. The outcomes of measurements on entangled quantum states can violate Bell inequalities [1], thus guaranteeing their intrinsic randomness. This constitutes the basis for certified randomness generation, which applies to untrusted devices [2,3]. However, this certification requires several spacelike separated devices, making it unfit for a compact apparatus [4]. Here we provide a general method for certified randomness generation on a small-scale application-ready device and perform an integrated photonic demonstration combining a solid-state emitter and a glass chip. In contrast to most existing certification protocols, which in the absence of spacelike separation are vulnerable to loopholes inherent to realistic devices [5], the protocol we implement accounts for information leakage to be compatible with emerging compact scalable devices. We demonstrate a 2-qubit photonic device that achieves the highest standard in randomness yet is cut out for real-world applications. The full 94.5-hour-long stabilized process harnesses a bright and stable single-photon quantum-dot based source, feeding into a reconfigurable photonic chip, with stability in the milliradian range on the implemented phases and consistent indistinguishably of the entangled photons above 93%. Using the contextuality framework [6], we robustly certify the highest standard of private randomness generation, i.e. cryptographic security even in the presence of quantum side information. This is a prototype for the controlled alliance of quantum hardware and protocols to reconcile practical limitations and device-independent certification.

we experimentally achieve state-of-the-art performance of a pigtailed solid-state quantum light emitter, with MHz pulsed count rate, high single-photon purity and indistinguishability. The source device performs with high stability over hours in rack-size cryostats and optical control modules for stand-alone operation.