Quantum information and its application to cryptography (MITACS QIP Seminar Series) - Michele Mosca

Quantum mechanics appears to fundamentally change some of the basic assumptions underlying modern cryptography. For example, factoring large numbers is in fact “easy” if we can build what we believe are “reasonable” physical devices. Eavesdropping is intrinsically detectable, and in a quantifiable way, if one uses an appropriate encoding of information. There are of course serious technological challenges to actually implementing most new quantum cryptographic protocols in practice (such as quantum money, which requires stable quantum memory). Nevertheless, some quantum cryptography technologies could be deployed in the short to medium term (in particular, quantum key establishment, also known as quantum key distribution (QKD)). However, at present there is limited interest in using QKD among applied cryptographers. I will discuss some of the practical challenges and argue why “QKD” should be taken more seriously when planning the cryptographic infrastructure of the future (joint work with D. Stebila and N. Lütkenhaus). I will also discuss the possibility of some futuristic quantum cryptographic protocols, such as quantum money (joint work with D. Stebila) and identification schemes (joint with L. Ioannou).