Dr. Umesh Vazirani, University of California, Berkeley
Abstract
PLEASE NOTE THE NEW COLLOQUIUM TIME AND LOCATION IN QNC.
Is it possible to certify that the n-bit output of a physical random
number generator is "really random"? In the classical World this seems
impossible.
Inspired by research in device independent quantum key distribution, in
2006 Colbeck observed that Bell inequality violations might provide a
way to achieve this in a quantum setting. In 2010, Pironio et. al. gave
a scheme for expanding sqrt(n) random bits to n certifiably random bits
using such an approach. In this talk I will discuss a scheme for
certifiably expanding the randomness by an exponential factor. Moreover
the output provably looks random even to a quantum adversary who is
allowed to tamper with the random generation devices. This strong
guarantee is based on the security of the Trevisan extractor against
quantum storage.
I will also touch upon very recent work that closes the circle, by
modifying the randomness extraction protocol to give the first complete
device independent proof of security of quantum key distribution that
tolerates a constant noise rate and generates a linear sized key.
Based on joint work with Thomas Vidick.