Quside

Quside builds quantum technologies for safer connectivity and more powerful computation. A spin-off of ICFO –The Institute of Photonic Sciences– in Barcelona, Spain, Quside is commercializing innovative hardware solutions for all connected devices. Quside is part of the European Quantum Flagship, collaborating in this ambitious initiative as an industry partner of the quantum communication projects CiViQ and QRANGE.

Random number generators and cryptography

Every time you send an email, connect to your bank account or check your medical examination, you rely on random numbers to protect the security of your online activity. Cryptography is the set of tools we use to keep us safe online, and random numbers are the foundation in which cryptography is built upon. In other words, if we could not generate unpredictable random digits, secure online communications would not be possible.

While there are many ways to generate “random numbers”, not all of them are good enough for cryptographic use. For instance, computers are unable to produce random digits on their own, unless we help them with external hardware means. The reason is simple: a computer is a machine designed to reliably execute one instruction after another, in a completely predictable and repeatable way.

That said, computers have functions and instructions to generate so-called pseudo-random numbers (PRNGs), which produce sequences of digits with certain “random” statistical properties. But the random numbers produced from a PRNG are completely predictable and therefore cannot be used “as is” for cryptographic applications.

The way to bring randomness (or unpredictability, to be more precise) to computers for cryptographic use is via so-called true random number generators (TRNGs).

How do true random number generators (TRNGs) work?

TRNGs are based on measuring a specific (random) physical process to produce random digits. Thus, the randomness of such numbers comes from the underlying physical process, which may indeed be completely unpredictable. TRNGs are the baseline for security applications.

TRNGs are hardware components and sophisticated engineering is required to build them properly. Unfortunately, current communication systems rely on weak TRNG designs, compromising security and/or performance of the communications. There are mainly two reasons for this reliance on weak TRNG designs. First, some systems do not even have a dedicated TRNG hardware component, due to cost or design choice, thus relying on generic components in the system to produce random samples (e.g., clock interrupts from the operating system).

Second, many TRNGs are designed based on physical principles that are complex and therefore produce “random-looking” dynamics (e.g., chaos), but which are, by principle, predictable and deterministic, which a sufficiently motivated attacker or a badly operated system may reveal to compromise security.

Building reliable, fast and unpredictable TRNGs is essential for the present and future of cryptography. And Quantum technologies are now being used to produce quantum-enhanced TRNGs, that is How do quantum number generators work.

What is a quantum random number generator?

Quantum random number generators (QRNGs) are a special case of TRNG, that generate randomness by measuring quantum processes, which are, by nature non-deterministic. The advantages are multiple, including a fundamental advantage in using quantum indeterminacy, typically faster performances by leveraging photonics and most importantly, the ability to understand and verify the origin of unpredictability, which is a core assurance for the entire cybersecurity chain.

Until now, engineering high-quality, scalable and fast quantum random number generators has been a challenge to date, and this is the area Quside has been pushing to advance over the last decade. Our proprietary technology allows for fast, high-quality, and scalable production, leading to a solution that is ready for today’s unpredictability concerns and tomorrow’s performance requirements.

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