Quantum Pioneers Bennett and Brassard Win Turing Award - The Tech Buzz
In the summer of 1979, Charles Bennett swam out to a stranger in the Atlantic Ocean off the coast of San Juan, Puerto Rico. The stranger was Gilles Brassard, a cryptographer who had just completed a dissertation on public-key cryptography. Bennett had an idea he wanted to share — one that belonged to a college classmate named Stephen Wiesner, who had conceived of quantum money that could not be counterfeited, and had struggled to get anyone in academia to listen. Brassard, treading water, listened politely. He was trapped, he later told Steven Levy at WIRED. Had he been on firm ground, he would have run.
The result of that ocean conversation was BB84 — a quantum key distribution protocol published in 1984 by Bennett and Brassard, named for their initials and the year. The core idea was elegant: exploit the quantum no-cloning theorem to make eavesdropping detectable. Any attempt to intercept a quantum signal necessarily disturbs it. A sender and receiver can therefore detect an intruder by comparing a sample of their transmitted bits. Bennett later described quantum information as like the information in a dream: attempting to share it changes your memory of the original. The public version can be copied, but it is not the same as the dream.
On Wednesday, the Association for Computing Machinery named Bennett and Brassard recipients of the 2025 ACM A.M. Turing Award, computing's highest honor, accompanied by a $1 million prize funded by Google. It is the first Turing Award associated with quantum research. In a statement, ACM President Yannis Ioannidis said the two laureates had fundamentally changed our understanding of information itself.
Bennett, 82, still works out of the IBM Thomas J. Watson Research Center in Yorktown Heights, New York. He joined IBM in the early 1970s, recruited by IBM Fellow Rolf Landauer, whose work on the thermodynamics of computation argued that information is not an abstraction but a physical quantity. Bennett's 1973 paper on the logical basis of computation, published before he met Brassard, laid groundwork that Landauer recognized as important. Brassard, 71, holds the Canada Research Chair in Quantum Computing at the Université de Montréal and has been a vocal public advocate for post-quantum cryptographic readiness — warning that the arrival of fault-tolerant quantum computers capable of breaking RSA encryption, which he calls Q-Day, is not a distant hypothetical but an urgent planning horizon.
The award arrives at a moment when the cryptographic infrastructure BB84 helped inspire is approaching a real-world stress test. NIST has finalized post-quantum cryptography standards. Organizations worldwide are in various stages of migration. Bennett and Brassard's work is suddenly relevant to infrastructure decisions being made right now, not just to the history of computer science.