The moment where quantum computers break encryption appears to be getting closer dem10/Getty Images Quantum computers could cause a global security crisis that makes the once-feared millennium bug, or Y2K, look quaint. This infamous computer risk was averted through the persistent behind-the-scenes work of engineers across the world, but whether the new threat will be tackled similarly is an urgent yet unresolved question. Most digital communications and transactions are protected by cryptography based on mathematical problems that are unsolvable by conventional computers but are solvable by a sufficiently capable quantum computer. Researchers have understood this since the late 1990s, but the day when this capable-enough quantum computer comes online – or Q-Day – was thought to be very far in the future. Much has changed since. Working quantum computers are now a reality, and recent leaps in how to use them are bringing Q-Day ever closer. Since the beginning of 2026, several studies have found that the two most common encryption methods, RSA-2048 and ECDLP-256, could be broken by quantum computers projected to exist by …