Deim Seminar
Title
On the optimization of non-perfect secret sharing schemes
Conferenciant
Torben Hansen
Professor/a organitzador/a
Oriol Farràs
Institution
Aarhus University
Date
19-12-2013 12:00
Summary
A secret sharing scheme is a method to protect data by dividing it
into pieces. These pieces are called shares and are generated in such
a way that data can only be fully recovered from certain subsets.
Secret sharing is an important primitive in cryptography, and
its security is unconditional, it derives from information theory
The first secret sharing schemes were constructed by Shamir and Blakley
in 1979. The original motivation was to protect keys and to safeguard
information, and so the shares were sent to a set of participants. The
subsets of participants whose shares can generate the secret, are
called authorized. In a perfect secret sharing scheme, the subsets
that are not authorized cannot obtain any information about the
secret. Because of that, the length of every share is at least the
length of the secret.
Non-perfect secret sharing schemes are schemes in which some
non-authorized subsets may obtain partial information about the secret
value. These schemes were first considered by Blakley and Meadows, who
introduced the threshold non-perfect secret sharing schemes, also
called ramp schemes. Differently to the perfect case, in a non-perfect
secret sharing scheme the length of some shares may be smaller than
the length of the secret, and so using these schemes we can construct
more efficient cryptographic protocols.
This talk will be dedicated to new results on the size of the shares of
non-perfect secret sharing schemes.
Torben Hansen is a master student of mathematics from the University
of Aarhus, Denmark, and he is visiting the URV.
Place
Lab 231 (a confirmar)
Language
Anglès
