Why quantum computers might break the internet's current locks

Technology · Published 24 October 2026 Swipe more like this →

In short: Every time you see a padlock in your browser, you are relying on math that is currently too hard for today's computers to solve. But as quantum physics moves from theory to technology, those mathematical walls are about to face a fundamental shift in how they work.

Modern digital security relies heavily on RSA cryptography, a system built on the difficulty of factoring large integers into prime numbers. When you visit a secure website or sign a document digitally, your data is protected by a public key and a private key. The security holds because it is currently too computationally intensive for standard computers to work backward from the public product to find the secret prime factors.

This foundation is threatened by Shor's algorithm, published in 1994 by Peter Shor. This mathematical framework describes how a quantum computer could theoretically factor incredibly large numbers with high efficiency. Because our current encryption methods are not necessarily secure against such machines, researchers are moving toward post-quantum cryptography—developing new systems based on math problems that even quantum computers cannot solve easily.

Alternatively, quantum cryptography uses the laws of physics rather than just math to protect data. By leveraging principles like superposition and entanglement, it aims to make undetected eavesdropping physically impossible. For example, the BB84 scheme involves sending single polarized photons; any attempt to intercept them alters their state. However, this approach faces massive engineering hurdles, such as decoherence—the fragility of quantum states—which requires extremely controlled environments and sophisticated error correction to maintain.

The transition represents a dual path: creating new math for current hardware (post-quantum) or building entirely new hardware based on quantum mechanics. While the latter offers a revolutionary leap in security, it remains a complex frontier of physics and engineering.

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