[Nets-seminars] Seminar on broadcast encryption and traitor tracing

[Mark Handley]

This Adastral Park seminar is being given at Gower Street, and
videolinked to Adastral.  It may be of interest to a number of you.

 - Mark

---------- Forwarded message ----------
From: Suzanne Bloomfield <s.bloomfield at adastral.ucl.ac.uk>
Date: May 23, 2006 12:13 PM
Subject: UCL ADASTRAL PARK SEMINAR SERIES - MONDAY 5TH JUNE
To: Suzanne Bloomfield <s.bloomfield at adastral.ucl.ac.uk>







UCL
Adastral Park Seminar Series




 Date:  Monday, 5th June 2006 Time:   3pm


Venue:
  UCL London EE Dept. Gower Street Room GS205
 Video linked to the UCL Adastral Park Campus, Ross Building

 Title:   A Broadcast Encryption Cryptosystem

 Speaker: Dr Brent Waters


Brent Waters is a Computer Scientist in the Principled Systems Group
in the Computer Science Laboratory at SRI International. He received
his B.S. degree from the University of California at Los Angeles
(2000) and his Ph.D. from Princeton University (2004). His primary
research interest is in applying cryptographic techniques to network
security problems. His recent work has focused on the topics of
privacy, message authentication, identity-based encryption, broadcast
systems, and methods for resisting denial-of-service attacks.


Abstract
A Broadcast Encryption cryptosystem allows a sender to encrypt a
message to some target set of users.  In a secure system users in the
target set can decrypt the ciphertext and no collusion of users
outside of the target set can learn anything about the message.
Broadcast encryption systems have a variety of applications. For
example, we could build a shared encrypted filesystem from broadcast
encryption where a user broadcast encrypts a file to the set of users
he wants to share it with. Broadcast encryption is also
 useful for large-scale content distribution; a content distributor
such as DirectTV or XMRadio will encrypt its digital media content to
the devices of all paying subscribers.

 The primary challenge with broadcast encryption is to design secure
systems with small ciphertext size. For example, we could achieve a
broadcast encryption scheme with ciphertexts linear in the number of
receivers by simply encrypting a message (or symmetric encryption key)
separately to each user the target set. However, this approach is
inefficient and becomes infeasible in large systems
 where there could be many users in a target set.

 In this talk I will present two recent developments in broadcast
encryption. First, I will discuss my work with Dan Boneh and Craig
Gentry on a broadcast encryption scheme that has constant ciphertext
size and constant size private keys. Our scheme can be used to encrypt
to arbitrary sets of users and is secure against an arbitrary number
of colluding attackers. Somewhat surprisingly, the only previous
fully-collusion resistant scheme is the trivial where we encrypt to
each user separately.

 Additionally, I will present some very recent work with Dan Boneh and
Amit Sahai on a related problem known as "Tracing Traitors". Our
tracing traitors construction allows us to trace a creator of a
"pirate box". Our solution achieves O(\sqrt(n)) size ciphertexts and
is secure against an arbitrary number of colluders.



For directions to EE Dept, 66-72 Gower Street, Room GS205
http://www.ee.ucl.ac.uk/people/map.html (the southern building marked
in red) http://www.ucl.ac.uk/images/map_arounducl_l.jpg
 http://www.ucl.ac.uk/images/map_mainsiteb&w.jpg



Please contact Suzanne Bloomfield on s.bloomfield at adastral.ucl.ac.uk
  if you wish to view at the Adastral Park Campus.
 For directions to Adastral Park
http://www.adastral-hub.com/travel/location.htm



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