Hi all,

today (Thursday), we have a seminar talk by Gus Gutoski at 2:30pm in the Alice Room.

Best wishes,
Markus



Title: Quantum one-time programs

Speaker: Gus Gutoski (IQC Waterloo)

Abstract:
A "one-time program" for a channel C is a hypothetical cryptographic primitive by which a user may evaluate C on only one input state of her choice.  (Think Mission Impossible: "this tape will self-destruct in five seconds.")  One-time programs cannot be achieved without extra assumptions such as secure hardware; it is known that one-time programs can be constructed for classical channels using a very basic hypothetical hardware device called a "one-time memory".

Our main result is the construction of a one-time program for any quantum channel specified by a circuit, assuming the same basic one-time memory devices used for classical channels.  The construction achieves universal composability -- the strongest possible security -- against any quantum adversary.  It employs a technique for computation on authenticated quantum data and we present a new authentication scheme called the "trap" scheme for this purpose.

Finally, we observe that there is a pathological class of channels that admit trivial one-time programs without any hardware assumptions whatsoever.  We characterize these channels, assuming an interesting conjecture on the invertible (or decoherence-free) subspaces of an arbitrary channel.

Joint work with Anne Broadbent and Douglas Stebila.
http://arxiv.org/abs/1211.1080


Date: Thursday, December 6, 2012 - 2:30 pm
Location: Alice Room (301)