CS Forum: Colin Boyd, NTNU "Forward Secrecy and Offline-Assisted Group Key Exchange"

CS forum is a seminar series arranged at the CS department - open to everyone free-of-charge. Coffee is served at 14:00 and the talk begins at 14:15.
Colin Boyd

Forward Secrecy and Offline-Assisted Group Key Exchange

Colin Boyd


Once viewed as an optional extra, in the post-Snowden era forward secrecy has become widely regarded as a necessity for key exchange protocols. It means that an adversary who obtains long-term keys of protocol participants should not be able to obtain the session key of a session which has completed. Forward secrecy is today usually provided for online communications using the widely deployed TLS protocol. Forward secrecy becomes more difficult to achieve in person-to-person communications such as email, instant messaging services, and peer-to-peer file sharing, because such communications are not interactive. Therefore different solutions are required in such scenarios.

In this talk I will (i) explain and illustrate the meaning and importance of forward secrecy; (ii) discuss ways to achieve forward secrecy in non-interactive protocols; (iii) describe a new group key exchange protocol with forward secrecy suitable for cloud storage environments.

This talk includes joint work with Gareth T. Davies, Kristian Gjøsteen and Yao Jiang and is funded by the Norwegian Research Council.


Colin Boyd completed a Ph.D. in Mathematics in 1995 from the University of Warwick, UK. After 5 years at British Telecom Research Laboratories, where he first became interested in cryptography and information security, he started an academic career at University of Manchester. In 1995 he emigrated to Australia and spent 18 years at Queensland University of Technology (QUT). During this time he was promoted to full professor in 2005 and became Research Director at the QUT Information Security Institute. In 2013 he returned to Europe, taking up a position as Professor in Information Security at the Norwegian University of Science and Technology (NTNU). His main research interests are in cryptographic protocols, especially key exchange. 

CS forum is a seminar series arranged at the CS department. The talks are intended for presentations of postdoctoral level researchers and professors, both for visiting and CS-department-based researchers.

  • Julkaistu:
  • Päivitetty: