Verifying Second-Level Security Protocols

A second-level security protocol is defined as a security protocol that relies on an underlying security protocol in order to achieve its goals. The verification of classical authentication protocols has become routine, but second-level protocols raise new challenges. These include the formalisation of appeals to the underlying protocols, the modification of the threat model, and the formalisation of the novel goals. These challenges have been met using Isabelle and the Inductive Approach [14]. The outcomes are demonstrated on a recent protocol for certified e-mail delivery by Abadi et al. [2].