Hi everyone,
Our group seminar will come out of its current lethargy on Monday with a
talk by Ben Fortescue.
Your ever-so-devoted seminar organizer,
--Frédéric
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Speaker: Ben Fortescue
Title: Going beyond the share size bound in quantum secret sharing.
Date/Time: Monday, June 27, 17:00
Place: When I find a room, you'll be the first to know.
Abstract:
Quantum secret sharing (QSS) is an important cryptographic protocol
which allows a quantum secret to be split between multiple "players",
such that only certain authorised player subsets may recover the secret.
It is, however, costly in terms of quantum communication and storage;
perfect QSS using quantum states requires every player's share to be at
least as large as the original secret.
I will discuss some of our recent results in which we improve upon this
bound through the use of imperfect "ramp" secret sharing, which allows
for smaller shares at the cost of weaker security. We find a specific
class of "entanglement sharing" ramp protocols, which allow for smaller
shares while still broadly restricting the protocols' information leakage.
Finally I will demonstrate how, by incorporating classical encryption
into "hybrid" QSS protocols, quantum share size can be reduced
(sometimes drastically) without requiring any reduction in security.