Graduate student Seyoon Ragavan led the work alongside senior author Vinod Vaikuntanathan, a computer science professor at MIT. The team published their paper through the IACR Cryptology ePrint Archive and presented it at the CRYPTO 2024 conference. The shadow of Shor’s algorithm The discovery builds directly on Shor’s algorithm, which MIT mathematician Peter Shor introduced three decades ago. Shor proved that a powerful enough quantum computer could crack massive security numbers faster than any regular computer. That finding posed a threat to RSA encryption, the security system developed at MIT in the 1970s. RSA still protects most internet traffic today because a standard computer would need millions of years to guess the secret keys. Why modern encryption is still safe No quantum computer today is powerful enough to actually run Shor’s algorithm for code-breaking. Experts estimate it would take 20 million quantum processing units, called qubits, to do it. The biggest quantum computers built so far have just over 1,100 qubits. Because of this hardware shortfall, modern encryption remains safe for now. In 2023, New York University computer scientist Oded Regev broke that streak. He found a way to cut down the number of steps the computer needs to take, marking the first big improvement since 1994. While Regev’s version was faster, it required a massive amount of quantum memory. Vaikuntanathan heard Regev present his work at a workshop, where Regev ended his talk with a challenge to the room: find a way to shrink that memory problem down. Ragavan and Vaikuntanathan decided to take on the challenge. A Fibonacci shortcut The new MIT system matches Regev’s fast speed but uses a fraction of the qubits, bringing the memory needs back down to Shor’s original levels. Crucially, the new method is also much better at handling the background noise that