This book constitutes the thoroughly refereed post-proceedings of the Third International Workshop on Formal Aspects in Security and Trust, FAST 2005, held in Newcastle upon Tyne, UK in July 2005. The 17 revised papers presented together with the extended abstract of one invited paper were carefully reviewed and selected from 37 submissions. The papers focus on formal aspects in security and trust policy models, and many other topics.

Voting Technologies and Trust.- On the Formal Analyses of the Zhou-Gollmann Non-repudiation Protocol.- Formal Reasoning About a Specification-Based Intrusion Detection for Dynamic Auto-configuration Protocols in Ad Hoc Networks.- A Formal Approach for Reasoning About a Class of Diffie-Hellman Protocols.- Eliminating Implicit Information Leaks by Transformational Typing and Unification.- Abstract Interpretation to Check Secure Information Flow in Programs with Input-Output Security Annotations.- Opacity Generalised to Transition Systems.- Unifying Decidability Results on Protection Systems Using Simulations.- Proof Obligations Preserving Compilation.- A Logic for Analysing Subterfuge in Delegation Chains.- Probable Innocence Revisited.- Relative Trustworthiness.- Secure Untrusted Binaries - Provably!.- Normative Specification: A Tool for Trust and Security.- Type-Based Distributed Access Control vs. Untyped Attackers.- A Security Management Information Model Derivation Framework: From Goals to Configurations.- On Anonymity with Identity Escrow.- Towards Verification of Timed Non-repudiation Protocols.