The Quantum Apocalypse: Understanding Q-Day and the Future of Encryption
One day soon, at a research lab near Santa Barbara or Seattle or a secret facility in the Chinese mountains, it will begin: the sudden unlocking of the world’s secrets. Cybersecurity analysts call this Q-Day—the day someone builds a quantum computer that can crack the most widely used forms of encryption.
These math problems have kept humanity’s intimate data safe for decades, but on Q-Day, everything could become vulnerable, for everyone: emails, text messages, anonymous posts, location histories, bitcoin wallets, police reports, hospital records, power stations, the entire global financial system. “We’re kind of playing Russian roulette,” says Michele Mosca, who coauthored the most recent “Quantum Threat Timeline” report from the Global Risk Institute, which estimates how long we have left.
The Quantum Technology Shift
Where today’s AI pushes the limits of classical computing—the kind that runs on 0s and 1s—quantum technology represents an altogether different form of computing. By harnessing the spooky mechanics of the subatomic world, it can run on 0s, 1s, or anything in between. This makes quantum computers potentially very good at, say, finding the recipe for a futuristic new material (or your email password).
The classical machine is doomed to a life of stepwise calculation: Try one set of ingredients, fail, scrap everything, try again. But quantum computers can explore many potential recipes simultaneously. Whoever wins the race won’t just have the next great engine of world-saving innovation; they’ll also have the greatest code-breaking machine in history.
The Vulnerability of RSA and Modern Cryptography
Take RSA encryption, developed in the late 1970s and still used for securing email, websites, and much more. In RSA, you (or your encrypted messaging app of choice) create a private key, which consists of two or more large prime numbers. Suppose you ask a classical computer to solve a simple math problem: Break the number 15 into its smallest prime factors. The computer would try all the options one by one and give you a near-instantaneous answer: 3 and 5. If you then ask the computer to factor a number with 1,000 digits, it would tackle the problem in exactly the same way—but the calculation would take millennia.
However, the quantum arms race has been heating up. Tech giants such as Google, Huawei, IBM, and Microsoft have been chasing quantum’s myriad positive applications—not only for materials science but also communications, drug development, and market analysis.
Quantum Threat Timeline and Probabilities
When Mosca and his colleagues surveyed cybersecurity experts last year, the forecast was sobering. The following data represents the estimated risks associated with the arrival of Q-Day:
- One-in-three chance: That Q-Day happens before 2035.
- 15 percent chance: The probability that Q-Day has already happened in secret.
Potential Scenarios for Q-Day
From a typical person’s vantage point, maybe Q-Day wouldn’t be recognizable as Q-Day at all. Maybe it would look like a series of strange and apparently unconnected news stories spread out over months or years. Alternatively, the holder of the universal picklock might prefer the disaster-movie outcome: everything, everywhere, all at once. This could include the following actions:
- Destroy the grid and plunge cities into darkness.
- Disable the missile silos.
- Take down the banking system.
- Open all the doors and let the secrets out.
China is plowing vast resources into state-backed efforts, and both the US and the European Union have pledged millions in funding to support homegrown quantum industries. So it’s normal to wonder: What kind of Q-Day will humanity get—and is there anything we can do to prepare?