[Busec] BUsec this week: Omer Paneth (Mon 10AM)

Sharon Goldberg goldbe at cs.bu.edu
Sun Apr 7 11:03:03 EDT 2013


This week at  seminar, Omer Paneth will be telling us about concurrent zero
knowledge in the global hash model.  Monday 10am in MCS137.
Next week we'll skip seminar due to Marathon Monday.

See you tomorrow!


BUsec Calendar: http://www.bu.edu/cs/busec/
BUsec Mailing list: http://cs-mailman.bu.edu/mailman/listinfo/busec

Title: Public-Coin Concurrent Zero-Knowledge in the Global Hash Model
Speaker: Omer Paneth, BU
Monday April 8, 10AM
Public-coin zero-knowledge and concurrent zero-knowledge (cZK) are two
classes of zero
knowledge protocols that guarantee some additional desirable properties.
Still, to this date
no protocol is known that is both public-coin and cZK for a language
outside BPP. Furthermore,
it is known that no such protocol can be black-box ZK [Pass et.al, Crypto
We present a public-coin concurrent ZK protocol for any NP language. The
assumes that all verifiers have access to a globally specified function,
drawn from a collision
resistant hash function family. (This model, which we call the Global Hash
Function, or
GHF model, can be seen as a restricted case of the non-programmable
reference string
model.) We also show that the impossibility of black-box public-coin cZK
extends also to
the GHF model.

Our protocol assumes CRH functions against quasi-polynomial adversaries and
O(log^{1+ \eps}(n)) rounds for any \eps > 0, where n is the security
parameter. Our techniques
combine those for (non-public-coin) black-box cZK with Barak's
non-black-box technique for
public-coin constant-round ZK. As a corollary we obtain the first
simultaneously resettable
zero-knowledge protocol with O(log^{1+ \eps}(n)) rounds, in the GHF model.

Joint work with Ran Canetti and Rachel Lin

Sharon Goldberg
Computer Science, Boston University
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://cs-mailman.bu.edu/pipermail/busec/attachments/20130407/b52491f9/attachment.html>

More information about the Busec mailing list