May 31, 2017 –
Title: Quantum Cryptography with Limited Resources: Semi-Quantum Key Distribution
Quantum Key Distribution (QKD) protocols allow two users, Alice (A) and Bob (B) to establish a secret key, secure against an all-powerful adversary - a task impossible to achieve using classical communication only. However, these protocols require A and B to both be capable of manipulating quantum resources in certain ways. We investigate the question: "How quantum does a protocol need to be in order to gain an advantage over classical protocols?" Can we achieve key distribution, secure against an all-powerful adversary, with less quantum capabilities?
This talk will focus on our investigation of a class of protocols known as Semi-Quantum Key Distribution (SQKD) Protocols, first introduced by Boyer, Kenigsberg, and Mor in 2007. Here, one user, typically Alice, is fully quantum and able to do whatever she likes with quantum resources. The other user, however, is "semi-quantum" in that he is severely limited in his quantum capabilities. Since their introduction in 2007, several SQKD protocols have been proposed - however none were proven unconditionally secure. We were the first to develop the techniques necessary to prove their security against all-powerful adversaries. Furthermore, we were able to show that several of these protocols have the same security properties as the standard "fully-quantum" protocols. While this is a very exciting theoretical result, it is also of practical interest as QKD equipment is in production and use today. Our work shows it is possible to still do key distribution, secure against an all-powerful adversary, with only limited hardware capabilities.
Walter O. Krawec earned a Ph.D. in Computer Science from Stevens Institute of Technology, Hoboken NJ in 2015, and an MA in Mathematics from the University at Albany (SUNY). Since graduating, he has been working at Iona College, New Rochelle NY and has taught several CS courses including Cryptography, Network Security, and Network Programming. His primary research interests are in quantum cryptography where he is currently interested in the design and security analysis of new quantum cryptographic protocols which require fewer quantum resources from the participating users.