categories: category theory applied to computer security

[Max Kelly <maxk@maths.usyd.edu.au>]

Keith Williamson asked about the above. Stefano Kasangian and I have
written something on this: 


S. Kasangian and Max Kelly, A bicategorical approach to information flow
and security, in  Categorical Studies in Italy, =  Rendiconti del
Circolo Matematico di Palermo, 64 (2000), 99 -- 122.

Max Kelly (= G.M. Kelly)