what is QRNG?

A quantum random number generator is a device that utilizes the
quantum phenomena to generate true random numbers. The
measurement outcome of the microscopic particles is inherently random, onesuch example is beam splitter scheme where we can
consider a photon sent to a beam splitter.

The probability of the photon to travel in transmitted path and reected path is same i.e. the photon remains in superposition of both the paths till it is detected in either one of the two detectors which are placed in the transmitted and reected path respectively and thus the outcome
is purely random.

A random number is a number generated which is unpredic
table, not
reproducible and unbiased. A random number can be produced by
either a software(de-terministic algorithm) or hardware (physical
process). A software generated random numbers are pseudo random
numbers because they can be reproduced after a period of time.

The physical random number generator (RNG) can be a classical
process which is deterministic or a quantum process which is
intrinsically random. The famous classical RNG which is coin tossing can
be pre
dicted if initial conditions are known. Thus pseudo random
numbers are reproducible and classical RNG are essentially complex
but yet deterministic. Genuine randomness is possible only by a
Quantum random number generator which is based on the
quantumness of microscopic system.

At present commercial QRNG are there in market for example qStream
of Quin
tessencelabs which can produce 1Gbit/s and QUANTIS
manufactured by IDQuantique can produce 16Mbits/s.

A quantum random number is an important resource and has many
demanding applications viz gaming industry, cryptography, statistical research, simulation, deterministic RNG seeding.