Master Thesis Defense - August 3, 2018: Short-lived Signatures

Michael Colburn

Friday, August 3, 2018 at 11:00 a.m.
Room EV003.309

You are invited to attend the following M.A.Sc. (Information Systems Security) thesis examination.

Examining Committee

Dr. J. Yan, Chair
Dr. J. Clark, Supervisor
Dr. A. Youssef, CIISE Examiner
Dr. L. Narayanan, External Examiner (CSSE)

Abstract

A short-lived signature is a digital signature with one distinguishing feature: with the passage of time, the validity of the signature dissipates to the point where valid signatures are no longer distinguishable from simulated forgeries (but the signing key remains secure and reusable). This dissipation happens "naturally" after signing a message and does not require further involvement from the signer, verifier, or a third party. This thesis introduces several constructions built from sigma protocols and proof of work algorithms and a framework by which to evaluate future constructions. We also describe some applications of short-lived signatures and proofs in the domains of secure messaging and voting.