For the first time, Professor Karimi's team was able to clone the photons that transmit information, namely the single carriers of light known as qubits, as well as quantum theory allows, meaning that the clones were almost exact replicas of the original information. However, in addition to undermining what was previously thought to be a perfect way of securely transmitting information, the researchers' analyses revealed promising clues into how to protect against such hacking.
"What we found was that when larger amounts of quantum information are encoded on a single photon, the copies will get worse and hacking even simpler to detect," said Frédéric Bouchard, a University of Ottawa doctoral student and lead author of an open access publication that appeared this month in the renowned journal Science Advances. "We were also able to show that cloning attacks introduce specific, observable noises in a secure quantum communication channel. Ensuring photons contain the largest amount of information possible and monitoring these noises in a secure channel should help strengthen quantum computing networks against potential hacking threats."
To read more, click here.