Accountable Anonymity

Some users may misbehave under the cover of anonymity by, e.g., defacing webpages on Wikipedia or posting vulgar comments on YouTube. To prevent such abuse, we have explored various anonymous credential schemes to revoke access for misbehaving users while maintaining their anonymity.

Our latest scheme, PERM, supports millions of user sessions and makes reputation-based blacklisting practical for large-scale deployments. Our other schemes include PEREA, BLAC, BLACR and Nymble.

People

Faculty
Apu Kapadia, Indiana University Bloomington
Man Ho Au, University of Wollongong, Australia

Publications

Man Ho Au and Apu Kapadia,
PERM: Practical Reputation-Based Blacklisting without TTPs,”
In Proceedings of The 19th ACM Conference on Computer and Communication Security (CCS ’12),
pp. 929–940, Raleigh, NC, October 16–18, 2012.
(bibtex)(acm)

Man Ho Au, Apu Kapadia, and Willy Susilo,
BLACR: TTP-Free Blacklistable Anonymous Credentials with Reputation,”
In Proceedings of The 19th Annual Network & Distributed System Security Symposium (NDSS ’12),
San Diego, CA, February 5–8, 2012.
(bibtex)(isoc)

Man Ho Au, Patrick P. Tsang, and Apu Kapadia,
PEREA: Practical TTP-Free Revocation of Repeatedly Misbehaving Anonymous Users,”
ACM Transactions on Information and System Security (ACM TISSEC),
Volume 14, Issue 4, Article 29, 34 pages (December 2011).
(Extends our CCS ’08 conference paper, which was Runner-up for PET Award 2009: Outstanding Research in Privacy Enhancing Technologies)
(bibtex)(acm)

Patrick P. Tsang, Apu Kapadia, Cory Cornelius, and Sean W. Smith,
Nymble: Blocking Misbehaving Users in Anonymizing Networks,”
IEEE Transactions on Dependable and Secure Computing (IEEE TDSC),
Volume 8, Number 2, pp. 256–269 (March–April 2011).
(bibtex)(ieee)(src/)(project)

Patrick P. Tsang, Man Ho Au, Apu Kapadia and Sean W. Smith,
BLAC: Revoking Repeatedly Misbehaving Anonymous Users Without Relying on TTPs,”
ACM Transactions on Information and System Security (ACM TISSEC),
Volume 13, Issue 4, Article 39, 33 pages (December 2010).
(Extends our CCS ’07 conference paper, which was Runner-up for PET Award 2009: Outstanding Research in Privacy Enhancing Technologies)
(bibtex)(acm)

Patrick P. Tsang, Man Ho Au, Apu Kapadia, and Sean W. Smith,
PEREA: Towards Practical TTP-Free Revocation in Anonymous Authentication,”
In Proceedings of The 15th ACM Conference on Computer and Communication Security (CCS ’08),
pp. 333–344, Alexandria, VA, October 27–31, 2008.
(Subsumed by our TISSEC Journal paper)
Runner-up for PET Award 2009: Outstanding Research in Privacy Enhancing Technologies
(bibtex)(acm)(free acm link)(pet award)

(This paper describes BLAC)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, and Sean W. Smith,
Blacklistable Anonymous Credentials: Blocking Misbehaving Users without TTPs,”
In Proceedings of the 14th ACM Conference on Computer and Communication Security (CCS ’07),
pp. 72–81, Alexandria, VA, October 29–November 2, 2007.
(Subsumed by our TISSEC Journal paper)
Runner-up for PET Award 2009: Outstanding Research in Privacy Enhancing Technologies
(bibtex)(acm)(free acm link)(journal version)(pet award)

Peter C. Johnson, Apu Kapadia, Patrick P. Tsang, and Sean W. Smith,
Nymble: Anonymous IP-Address Blocking,”
In Proceedings of the Seventh International Symposium on Privacy Enhancing Technologies (PET ’07),
pp. 113–133, Ottawa, Canada, June 20–22, 2007. © Springer-Verlag, LNCS 4776.
(Subsumed by our TDSC Journal paper)
(bibtex)(springer)(src/)(project)