**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).