Scientists all over the world are searching for pure randomness

Scientists all over the world are searching for pure randomness

You take the interstate to get home and rely on the water utility for a drink. But have you ever felt the need for some publicly available randomness?

Governments and researchers around the world think you might, with projects in the works to produce public sources, or "beacons," of randomness. From quantum-physics experiments to distributed projects that anyone with a laptop could help produce, a wide range of efforts aim to bring randomness to your fingertips.

Publicly available randomness helps ensure online security, free elections and fair immigration practices - and may even help address deep questions about the nature of the universe. But producing these randomness beacons ­­- secure, truly random numbers that the public can trust - ­poses huge challenges, sending researchers into the quantum realm and beyond in search of fundamentally unpredictable phenomena. Here's why scientists see randomness as a public utility - and how they're trying to make a mess for your sake.

Scientists Across the Globe Are Hunting for Pure Randomness
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You take the interstate to get home and rely on the water utility for a drink. But have you ever felt the need for some publicly available randomness?

Governments and researchers around the world think you might, with projects in the works to produce public sources, or "beacons," of randomness. From quantum-physics experiments to distributed projects that anyone with a laptop could help produce, a wide range of efforts aim to bring randomness to your fingertips.

Publicly available randomness helps ensure online security, free elections and fair immigration practices — and may even help address deep questions about the nature of the universe. But producing these randomness beacons ­­— secure, truly random numbers that the public can trust — ­poses huge challenges, sending researchers into the quantum realm and beyond in search of fundamentally unpredictable phenomena. Here's why scientists see randomness as a public utility — and how they're trying to make a mess for your sake.


What counts as random?

We've all experienced it, but may not know exactly what it is: Randomness is the level of disorder and unpredictability in a system.True, pure randomness is fundamentally unpredictable, said physicist Krister Shalm, who leads quantum experiments for the U.S. National Institute of Standards and Technology (NIST). For instance, if you watched a source of truly random numbers forever, over time, your odds of getting any given number would be the same. (Randomness differs slightly from the related term entropy, which is a numerical measure of disorder.)

Why would anyone want to increase disorder in the world? It turns out, public sources of randomness can aid in a number of tasks, from safeguarding complex cryptography to shuffling card decks in online games, said Ewa Syta, a computer scientist at Trinity College in Connecticut.

"Public randomness is used in … any kind of system that requires some way to make a decision … to do anything where you want some fair way to agree upon things," Syta had said. "Basically, what public randomness gives you is a way to implement a fair coin toss."

The public part of these projects guarantees that multiple parties can verify and trust that toss, said Michael Fischer, a Yale University computer scientist who consulted on a new government beacon of randomness. Not only are the beacons' outputs freely available, but the underlying methods and the output's archives are also public.

"You want choices that are free of influence from people with particular agendas," Fischer said.

Surprisingly elusive randomness

Creating these public spigots of entropy, or randomness beacons, however, is extremely challenging. These beacons use a variety of sources for their disorder, from physical processes like photon emissions or seismic rumblings, to long strings of tweets fed through cryptographic transformations. Whatever the source, though, beacon producers have similar goals: The output should be unpredictable, autonomous and consistent (meaning different users can expect to get the same random string from the beacon), according to NIST. The latter two traits greatly affect trust and usability. The first one addresses the heart of randomness, according to NIST.

"That question, how do you know if something's truly random, that's a really deep and difficult problem," Shalm had said.

The key is unpredictability, he said. While many things in nature appear chaotic, they almost always have underlying structures or order that someone could, in theory, use to make predictions. That makes finding truly random — fundamentally unpredictable — numbers devilishly hard. For example, Shalm said, think of a football game's coin toss, that icon of randomness. "If you knew exactly how much pressure the referee was applying to the coin and, as it flips in the air, how much turbulence interacts with it, you can predict exactly how that thing's going to land," he said.

Similar criticism applies to (almost) any random-number generator based on a physical process, Shalm said. And software-based generators can also be predicted because they follow algorithms, said Rene Peralta, a computer scientist who is running a randomness beacon project for NIST.

Where's the randomness?

The researchers at NIST began their search for entropy sources in the quantum realm. Quantum mechanics, at its heart, is a random theory, Shalm said. For example, you can't predict exactly when a particular radioactive atom will decay — only a probability, wrote Scott Aaronson, the director of the Quantum Information Centre at The University of Texas at Austin.

"Quantum mechanics … says that things happen randomly," Shalm said. "You can't predict what's going to happen exactly — you can only predict probabilities."

So, the current NIST beacon relies, in part, on a quantum-based random number generator; this device measures the arrival time of photons produced by an attenuated laser, which emits photons at random times, Shalm said. (Think of this laser like a narrowed water spigot, but for light, he said.) The NIST beacon combines that output with the production of commercial random number generators, which rely on electronic-circuit noise instead of quantum properties, upping the combined entropy with mathematical transformations.

Chile's beacon, meanwhile, draws on seismic data in the earthquake-prone country, plus Twitter feeds. Long strings of concatenated tweets are "pretty unpredictable, because you don't know ahead what people are going to say," Peralta said. A cryptographic hash shrinks these long strings, removing the structure characteristic of language and producing something "pretty much uniformly random," he said.

The distributed models can draw randomness both from individuals running entropy-producing programs on their laptops and from private companies, like Cloudflare, which extracts randomness from lava lamps. The company snaps high-resolution photos of a wall of lamps' shifting, disordered patterns.

So, the next time you flip a coin think, was that truly random?