Comparing social security programs with leisure and bequests

This paper compares social security programs in the AK model with leisure and bequests. It will show that the unfunded program with contribution-dependent benefits has smaller distortions than programs (funded or unfunded alike) with contribution-independent benefits. (C) 2002 Elsevier Science B.V. All rights reserved.

Formal verification of type flaw attacks in security protocols

Security protocols are often modelled at a high level of abstraction, potentially overlooking implementation-dependent vulnerabilities. Here we use the Z specification language's rich set of data structures to formally model potentially ambiguous messages that may be exploited in a 'type flaw' attack. We then show how to formally verify whether or not such an attack is actually possible in a particular protocol using Z's schema calculus.