  Random number generators are essential to ensure performance in information
technologies, including cryptography, stochastic simulations and massive data
processing. The quality of random numbers ultimately determines the security
and privacy that can be achieved, while the speed at which they can be
generated poses limits to the utilisation of the available resources. In this
work we propose and demonstrate a quantum entropy source for random number
generation on an indium phosphide photonic integrated circuit made possible by
a new design using two-laser interference and heterodyne detection. The
resulting device offers high-speed operation with unprecedented security
guarantees and reduced form factor. It is also compatible with complementary
metal-oxide semiconductor technology, opening the path to its integration in
computation and communication electronic cards, which is particularly relevant
for the intensive migration of information processing and storage tasks from
local premises to cloud data centres.
