What is a random number and why quantum?
A random number is a number generated by a process, whose outcome is completely unpredictable, and which cannot be subsequently reliably reproduced.
Although random numbers are required in many applications — from cryptosystems to gaming — their generation is often overlooked. In order to guarantee absolutely random numbers, RNGs must not be vulnerable to prediction or bias, and thus dictated by true randomness.
The problem arises from how the keys are created. Most systems use a process called ‘Pseudo Random Number Generation’ (PRNG). Why ‘pseudo’? Because, due to their deterministic nature, conventional computers cannot generate true randomness. Information from inputs such as mouse movements, keyboard pressures, disc interrupts or system timers are all placed into a ‘pool’ of numbers, from which a ‘seed’ is picked. This ‘seed’ is then used in the PRNG which generates the keys.
The better solution is to use hardware random number generation. However, not all hardware random number generators are equally good. Many hardware random number generators still rely on classical physics to produce what looks like a random stream of bits. In reality, determinism is hidden behind complexity for RNGs that do not exploit quantum physics.
Contrary to classical physics, quantum physics is fundamentally random. It is the only theory within the fabric of modern physics that integrates randomness. Quantum Random Number Generators (like the Quantis range from IDQ) use these quantum-random properties to generate truly random numbers.
In addition, Quantum Random Number Generators (QRNG) have the advantage over conventional randomness sources of being invulnerable to environmental perturbations and of allowing live status verification.