Why Isn't Trust Transitive? - Bruce Christianson; William S. Harbison (Security Protocols Workshop, 1996)

Trusting in computer systems. - William S. Harbison (1997)

Delegating Trust (Transcript of Discussion). - William S. Harbison (Security Protocols Workshop, 1998)

Government Access to Keys - Panel Discussion. - Michael Roe; Ross J. Anderson; William S. Harbison; T. Mark A. Lomas (Security Protocols Workshop, 2000)