A Logic for Constraint-based Security Protocol Analysis

We propose PS-LTL, a pure-past security linear temporal logic that allows the specification of a variety of authentication, secrecy and data freshness properties. Furthermore, we present a sound and complete decision procedure to establish the validity of security properties for symbolic execution traces, and show the integration with constraint-based analysis techniques

Proceedings of the 3rd International Workshop on Formal Aspects in Security and Trust (FAST2005)

The present report contains the pre-proceedings of the third international Workshop on Formal Aspects in Security and Trust (FAST2005), held in Newcastle upon Tyne, 18-19 July 2005. FAST is an event affliated with the Formal Methods 2005 Congress (FM05). The third international Workshop on Formal Aspects in Security and Trust (FAST2005) aims at continuing the successful effort of the previous two FAST workshop editions for fostering the cooperation among researchers in the areas of security and trust. The new challenges offered by the so-called ambient intelligence space, as a future paradigm in the information society, demand for a coherent and rigorous framework of concepts, tools and methodologies to provide user\u27s trust&confidence on the underlying communication/interaction infrastructure. It is necessary to address issues relating to both guaranteeing security of the infrastructure and the perception of the infrastructure being secure. In addition, user confidence on what is happening must be enhanced by developing trust models effective but also easily comprehensible and manageable by users

Temporal rank functions for forward secrecy

A number of cryptographic protocols have appeared in the literature that claim to provide forward secrecy. The idea of forward secrecy is that if a long-term key is compromised then any session-keys that were previously established using the long-term key should remain secret. Forward secrecy is important in scenarios where session-keys need protection beyond the time-span during which they are used. These situations typically arise when session-keys are used for data encryption, rather than just authentication. There appears to be a disparity between the growing number of protocols that claim forward secrecy, and the work carried out on its formal analysis. In contrast to secrecy and authentication, the formal verification of forward secrecy has, with some exceptions received little attention in the literature. This paper fills the gap for the rank function approach