Professor of Computer Science at Royal Holloway, University of London since March 1990
Project Manager at Hewlett-Packard Laboratories, Bristol (June 1985 – March 1990)
Worked at Racal-Comsec Ltd., Salisbury, UK (1979–1985), latterly as Chief Mathematician
Full-time consultant at Europay International, Belgium during the 1996–97 academic year
Participated in multiple international collaborative projects including Open Trusted Computing, Distributed Trust, Mobile VCE, USB_Crypt, PAMPAS, SHAMAN, Finger_Card, and USECA
Member of the EPSRC-funded Network of Excellence on Digital Electronic Identity (2008–2010)