Kristiyan Haralambiev
New York University

TITLE:
Efficient Ring Signatures without Random Oracles

ABSTRACT:
We describe the first efficient ring signature scheme secure, without random
oracles, based on standard assumptions. Our ring signatures are based in
bilinear groups. For $l$ members of a ring our signatures consist of $2l+2$
group elements and require $2l+3$ pairings to verify. We prove our scheme secure
in the strongest security model proposed by Bender, Katz, and Morselli: namely,
we show our scheme to be anonymous against full key exposure and unforgeable
with respect to insider corruption. A shortcoming of our approach is that all
the users' keys must be defined in the same group.

Authors:
Hovav Shacham and Brent Waters