Charles H. Bennett and Gilles Brassard have been awarded the 2025 ACM A.M. Turing Award for “their essential role in establishing the foundations of quantum information science and transforming secure communication and computing.” The award, often referred to as the “Nobel Prize of Computing,” carries a $1 million prize. It is the first time the 60-year-old prize honours work in the quantum realm.
Bennett, a physicist at IBM Research, and Brassard, a computer scientist at the Université de Montréal, began their collaboration in 1979 at a computing conference in Puerto Rico, where Bennett famously swam up to Brassard at the beach to discuss their shared interest in combining quantum mechanics and information theory. Over four decades and more than two dozen joint papers, they helped create the field of quantum information science.
In 1984, inspired by the insights of their late collaborator Stephen Wiesner, Bennett and Brassard invented the BB84 protocol, which allows two parties to establish a secure cryptographic key by exchanging single photons. Unlike conventional public-key cryptography, BB84 achieves information-theoretic security without computational assumptions, instead relying on a fundamental property of quantum information: it cannot be copied or measured without disturbance. Any attempt at eavesdropping leaves detectable traces. The paper kicked off the subfield of quantum cryptography, and quantum key distribution systems are now being tested in experimental networks around the world.
In 1993, they and colleagues introduced quantum teleportation, demonstrating how entanglement — once viewed primarily as a philosophical curiosity — could serve as a practical resource for transmitting quantum states between distant parties. Experimental verification of related phenomena was recognised by the 2022 Nobel Prize in Physics. In 1996, they introduced entanglement distillation, a technique for generating higher-quality entangled pairs from lower-quality ones. Both quantum teleportation and entanglement distillation are expected to be essential building blocks for quantum networks and ultimately a quantum internet.
“Bennett and Brassard fundamentally changed our understanding of information itself,” said ACM President Yannis Ioannidis. “Their insights expanded the boundaries of computing and set in motion decades of discovery across disciplines.”
Bennett and Brassard previously shared the 2023 Breakthrough Prize in Fundamental Physics with Peter Shor and David Deutsch. The prize ceremony brought them to Amsterdam for events at CWI, QuSoft, and the Royal Netherlands Academy of Arts and Sciences (KNAW).
QuSoft is particularly proud of this recognition. Brassard held the Turing Chair for Quantum Software at the University of Amsterdam, a rotating honorary position associated with QuSoft, and has been involved with QuSoft since its establishment in 2015. He serves on QuSoft’s Scientific Advisory Board and remains a welcome and frequent guest. His foundational contributions laid the groundwork for the research field many researchers within QuSoft are working on today. As QuSoft’s Harry Buhrman put it: Bennett and Brassard “had the spark of this idea that turned into this quantum fire we’re in now.”
