Fang Song: Cryptography in a quantum world

Wednesday, February 6, 2013 2:00 pm - 3:00 pm EST (GMT -05:00)

Fang Song, Penn State University

Abstract

Cryptography can change dramatically in a quantum world where people can process quantum information. On the one hand, there are specific quantum attacks that break classically secure constructions, and in general security against classical adversaries may become invalid when adversaries become quantum. On the other hand, we can also design quantum protocols which sometimes can achieve tasks that are otherwise impossible using classical protocols only, e.g., quantum key distribution with statistical security.

In this talk, I will present two main results of my research work. First, I will show a general feasibility result that there exist classical protocols for 2-party Secure Function Evaluation against quantum adversaries, under proper assumptions [HSS'11]. Second, I will show a quantum protocol that realizes Oblivious Transfer with statistical security from a trusted setup called 2-bit Cut-and-Choose [FKSZZ'13]. This reduction is provably impossible if using classical protocol only.

[HSS'11] Classical Cryptogrphic Protocols in a Quantum World. Sean Hallgren, Adam Smith and Fang Song. In Crypto 2011.

[FKSZZ'13] Feasibility and Completeness of Cryptographic Tasks in the Quantum World. Sergh Fehr, Jonathan Katz, Fang Song, Hong-Sheng Zhou and Vassilis Zikas. To appear in TCC 2013.