Université de Montréal computer science professor Gilles Brassard has been honored with the highest distinction in his field for his work on quantum cryptography, a technology that could revolutionize computer security.
It is peer recognition of almost half a century of work. I couldn’t be happier
exclaimed Mr. Brassard, in an interview on the show All one morningWednesday.
With his colleague, IBM physicist Charles H. Bennett, the Quebecer was awarded the 2025 A. M. Turing Prize, named after the British mathematician who unraveled the mystery of the German “Enigma” encryption machine during the Second World War. He is recognized today as the father of computing.
Like Alan Turing, the work of Gilles Brassard and Charles H. Bennett is shaking up the science of encryption, this time by giving it a quantum twist.
The operation of quantum computers is complex, since these machines process information at the scale of elementary particles, such as protons and electrons, where the laws of physics are different from ours. (Archive photo)
Photo: The Canadian Press / Seth Wenig
The researchers notably developed the very first quantum cryptography protocol, named BB84 (from their initials and the year of their invention). This protocol allows information to be transmitted securely using the principles of quantum theory, which focuses on the infinitely small.
It is about using the properties of the microscopic world, which are a little different, even very different, from those to which we are accustomed in our macroscopic world
explains Gilles Brassard.
In particular, information, at this level, cannot be measured without disturbance and any attempt to measure it creates a disturbance which can be detected.
Thus, the messages transmitted using its protocol are theoretically impossible to decipher for anyone who manages to intercept them, and any attempt at espionage would be immediately detected.
The evil and the cure
The BB84 protocol is already used as a model to protect highly confidential communications via optical fiber and satellites. But quantum cryptography is not taken seriously enough in North America, laments the professor.
Sadly, it is especially used in China. They took it very seriously and developed 10,000 km of optical fiber — a complete quantum communications network — for cryptography specifically
he emphasizes.
Quantum communications work via optical fiber since they often rely on the state of a photon. (Archive photo)
Photo : Radio-Canada
From another aspect, the rise of quantum computing, for cryptology, is causing a commotion in terms of computer security.
The appearance and development of quantum computers, which can carry out very large volumes of calculations simultaneously, portend the obsolescence of current security systems.
Entire infrastructure is compromised by the emergence of quantum computers
estimates Gilles Brassard.
The quantum computer will be able to completely break all the cryptography and security that has been in place on the Internet for 40 years.
However, since it will allow both the encryption of messages and their decryption, it is quantum theory which is [à la fois] the disease and the cure
notes the cryptologist.
But it’s even more ironic, because the cure was discovered 10 years before the disease.
he says, referring to quantum cryptology, of which his BB84 security protocol is a part.
What is a quantum computer?
Traditional computing systems, such as the computers and telephones you are reading this article with, use a binary system to calculate operations, called bits
. The bits take either a value of 0 or 1. They are either open
either closed
.
Most quantum computers around the world use superconducting qubits. A qubit is a unit that allows the computer to perform calculations, like bits for classical computers. While bits are restricted to taking the form of either 0 or 1, qubits can take any value between 0 and 1 inclusive, in addition to taking all of these values simultaneously.
They are therefore more efficient, but not necessarily faster: they simply perform all operations in parallel, rather than in series.
The IBM Q System One quantum computer is enclosed in a large glass cube measuring 2.74 meters on each side. (Archive photo)
Photo : IBM
No way
to go to the United States
The award, funded by Google, includes a US$1 million grant.
Notably, Gilles Brassard did not go to the New York headquarters of theAssociation for Computing Machinery lto receive it.
I completely boycott the United States, whether for travel or to buy a pack of spinach. If an ingredient comes from the United States, I change the recipe
curses the winner. No question of going to a country that has literally declared war on us.
