Verifying a Mix Net in CSP

A Mix Net is a cryptographic protocol that tries to unlink the correspondence between its inputs and its outputs. In this paper, we formally analyse a Mix Net using the process algebra CSP and its associated model checker FDR. The protocol that we verify removes the reliance on a Web Bulletin Board during the mixing process: rather than communicating via a Web Bulletin Board, the protocol allows the mix servers to communicate directly, exchanging signed messages and maintaining their own records of the messages they have received. Mix Net analyses in the literature are invariably focused on safety properties; important liveness properties, such as deadlock freedom, are wholly neglected. This is an unhappy omission, however, since a Mix Net that produces no results is of little use. Here we verify that the Mix Net is guaranteed to terminate, outputting a provably valid mix agreed upon by a majority of mix servers, under the assumption that a majority of them act according to the protocol

Keeping Fairness Alive : Design and formal verification of optimistic fair exchange protocols

Fokkink, W.J. [Promotor]Pol, J.C. van de [Promotor

A Survey of Verification Techniques for Security Protocols

Security protocols aim to allow secure electronic communication despite the potential presence of eavesdroppers. Guaranteeing their correctness is vital in many applications. This report briefly surveys the many formal specification and verification techniques proposed for describing and analysing security protocols

Integration of analysis techniques in security and fault-tolerance

This thesis focuses on the study of integration of formal methodologies in security protocol analysis and fault-tolerance analysis. The research is developed in two different directions: interdisciplinary and intra-disciplinary. In the former, we look for a beneficial interaction between strategies of analysis in security protocols and fault-tolerance; in the latter, we search for connections among different approaches of analysis within the security area. In the following we summarize the main results of the research

Utilization of timed automata as a verification tool for real-time security protocols

Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2010Includes bibliographical references (leaves: 85-92)Text in English; Abstract: Turkish and Englishxi, 92 leavesTimed Automata is an extension to the automata-theoretic approach to the modeling of real time systems that introduces time into the classical automata. Since it has been first proposed by Alur and Dill in the early nineties, it has become an important research area and been widely studied in both the context of formal languages and modeling and verification of real time systems. Timed automata use dense time modeling, allowing efficient model checking of time-sensitive systems whose correct functioning depend on the timing properties. One of these application areas is the verification of security protocols. This thesis aims to study the timed automata model and utilize it as a verification tool for security protocols. As a case study, the Neuman-Stubblebine Repeated Authentication Protocol is modeled and verified employing the time-sensitive properties in the model. The flaws of the protocol are analyzed and it is commented on the benefits and challenges of the model

Chosen-name Attacks:An Overlooked Class of Type-flaw Attacks

In the context of Dolev-Yao style analysis of security protocols, we consider the capability of an intruder to dynamically choose and assign names to agents. This capability has been overlooked in all significant protocol verification frameworks based on formal methods. We identify and classify new type-flaw attacks arising from this capability. Several examples of protocols that are vulnerable to this type of attack are given, including Lowe’s modification of KSL. The consequences for automatic verification tools are discussed

A framework for proving the correctness of cryptographic protocol properties by linear temporal logic

In this paper, a framework for cryptographic protocol analysis using linear temporal logic is proposed. The framework can be used to specify and analyse security protocols. It aims to investigate and analyse the security protocols properties that are secure or have any flaws. The framework extends the linear temporal logic by including the knowledge of participants in each status that may change over the time. It includes two main parts, the Language of Temporal Logic (LTL) and the domain knowledge. The ability of the framework is demonstrated by analysing the Needham-Schroeder public key protocol and the Andrew Secure RPC protocol as examples