The origin of quantum cryptography
Gilles Brassard (Université de Montréal, Canada)

Quantum Key Distribution (QKD) makes it possible for two participants to exchange messages in provable perfect confidentiality under the nose of an eavesdropper whose computational power is unlimited and whose technology is restricted only by the accepted laws of physics. Despite a classical theorem of Shannon to the contrary, this is possible even though the two participants do not share ahead of time a secret key as long as the message they wish to transmit. As such, QKD is the first near-term practical application of the emerging field of quantum information processing. In this talk, we shall tell the tale of the origin of QKD from the birth of the first idea by Wiesner in 1970 to the invention of the first QKD scheme, known as BB84, twenty-five years ago, to exciting prospects for the future.