By Katie Hunt, CNN
(CNN) — Years before emails, internet banking, cloud servers and cryptocurrency wallets, two scientists devised a way to keep secrets perfectly safe and indecipherable to eavesdropping outsiders.
Their 1984 work depended on the hidden, counterintuitive world of quantum physics, which governs the way the world works at the smallest, subatomic scale, rather than complex but theoretically breakable mathematical codes to secure data.
The insights of Charles Bennett, an American physicist who is a fellow at IBM Research, and Gilles Brassard, a Canadian computer scientist and professor at the University of Montreal, have since transformed cryptography and computing. The pair received the A.M. Turing Award on Wednesday for their groundbreaking work on quantum key cryptography. Named after the late mathematician and wartime codebreaker Alan Mathison Turin, who articulated the mathematical foundations of computing, the honor is widely considered the Nobel Prize of computer science.
“Cryptography is a fundamental pillar of the global economy and our safety and our security and our sovereignty. It’s really the invisible background plumbing,” said Michele Mosca, cofounder and CEO of cybersecurity company evolutionQ and a professor at the Institute for Quantum Computing at the University of Waterloo in Ontario. He said it is “wonderful” that Bennett and Brassard have won the award, which comes with a $1 million prize.
Bennett and Brassard initially struggled to get their work taken seriously, but it has since taken on more urgency and significance. Security experts fear what’s known as “Q day” or quantum day: the development of a quantum computer powerful enough to hack the mathematical encryption keys, such as RSA, that currently keep most internet communication safe, potentially resulting in the biggest release of secrets in history.
Internet security is currently based on public key encryption that essentially relies on a quirk of math: While multiplying numbers is relatively easy, the inverse of that process — factorizing — is not.
However, it’s possible a full-scale quantum computer, which many experts say will be feasible in the mid-2030s, has the potential to crack the mathematical codes that protect sensitive information. This breakthrough could result in huge breaches in the security of communications over the internet, Brassard said.
Quantum computers work in a completely different way than typical machines today, which store and process information in bits, using a language made up of zeros and ones. Quantum computers use “quantum bits,” also known as “qubits,” which can behave like zero and one simultaneously, a quantum state known as superposition. In theory, this ability will allow quantum computers to process information much more quickly.
With current computing, a padlock symbol in your internet browser is a symbol that suggests that a transaction or exchange is taking place securely, Brassard said. “But this is given to you by techniques that are completely broken or will be by a quantum computer when we have one.”
Bad actors may already be collecting encrypted data, with a view to “harvest now, decrypt later” attacks, Brassard, Mosca and other analysts have noted, in which all information can be taken down, stored and decrypted when a quantum computer is available.
The quantum key cryptography conceived by Brassard and Bennett, however, allows information to be transmitted in a fundamentally secure way that can’t be hacked, not even with a quantum computer.
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