The Algorithm That Threatened Everything

In 1994, mathematician Peter Shor published a paper that sent ripples through the cryptography community. An algorithm that could factor large numbers exponentially faster than any classical method.

To mathematicians, an elegant theoretical result. To security experts, potentially catastrophic.

Modern encryption depends on mathematical difficulty. Problems easy to create but practically impossible to reverse.

RSA encryption secures most internet communications, financial transactions, and classified data. It relies on a simple principle.

Multiplying two large prime numbers is trivially easy. Finding those original primes from the product is practically impossible.

A 2048 bit RSA key would take classical supercomputers longer than the age of the universe to crack.

Shor's algorithm changed this calculation. On a quantum computer, the same factorization could be accomplished efficiently. Not in billions of years but in hours or days.

> Every secret protected by RSA would become readable. The mathematical lock protecting the digital world could be picked.

There was a significant catch. Shor's algorithm required a quantum computer. In 1994, such machines existed only in theory.

Building one presented engineering challenges that seemed impossibly difficult. Quantum states are extraordinarily fragile. They collapse under observation. They decohere in the presence of heat and interference.

Maintaining enough stable quantum bits seemed to require solving problems physics itself might forbid.

For years, the threat remained theoretical. Researchers built small systems with a handful of qubits. Proof of concept experiments confirming quantum computing was possible.

But nothing approached practical cryptographic attacks. The thousands of stable qubits required remained safely distant.

Then progress accelerated. Google assembled teams of physicists and engineers. IBM invested billions. Government laboratories poured resources into the field.

The motivations were not primarily cryptographic. Quantum computers promised breakthroughs in drug discovery, optimization, machine learning. Breaking encryption was almost incidental.

By the late 2010s, quantum computers with dozens of qubits were operational. Still far from what Shor's algorithm required.

But the trajectory was unmistakable. Each year brought more qubits. Better error correction. Longer coherence times.

> The impossible was becoming merely difficult. The difficult was becoming expensive but achievable.

The cryptography community began preparing for a future that once seemed distant but now appeared to be approaching fast.