Formal Analysis of Quantum Systems using Process Calculus

Quantum communication and cryptographic protocols are well on the way to becoming an important practical technology. Although a large amount of successful research has been done on proving their correctness, most of this work does not make use of familiar techniques from formal methods, such as formal logics for specification, formal modelling languages, separation of levels of abstraction, and compositional analysis. We argue that these techniques will be necessary for the analysis of large-scale systems that combine quantum and classical components, and summarize the results of initial investigation using behavioural equivalence in process calculus. This paper is a summary of Simon Gay's invited talk at ICE'11.Comment: In Proceedings ICE 2011, arXiv:1108.014

Easing the Transition from Inspiration to Implementation: A Rapid Prototyping Platform for Wireless Medium Access Control Protocols

Packet broadcast networks are in widespread use in modern wireless communication systems. Medium access control is a key functionality within such technologies. A substantial research effort has been and continues to be invested into the study of existing protocols and the development of new and specialised ones. Academic researchers are restricted in their studies by an absence of suitable wireless MAC protocol development methods. This thesis describes an environment which allows rapid prototyping and evaluation of wireless medium access control protocols. The proposed design flow allows specification of the protocol using the specification and description language (SDL) formal description technique. A tool is presented to convert the SDL protocol description into a C++ model suitable for integration into both simulation and implementation environments. Simulations at various levels of abstraction are shown to be relevant at different stages of protocol design. Environments based on the Cinderella SDL simulator and the ns-2 network simulator have been developed which allow early functional verification, along with detailed and accurate performance analysis of protocols under development. A hardware platform is presented which allows implementation of protocols with flexibility in the hardware/software trade-off. Measurement facilities are integral to the hardware framework, and provide a means for accurate real-world feedback on protocol performance

A verification concept for SDL systems and its application to the Abracadabra protocol

SDL is a specification language to specify distributed systems. Especially it is suitable for communication protocols. In some cases however it is not enough to describe just the behaviour of a protocol, but there are formulated some additional properties as requirements of the SDL system. A formalism convenient to describe them is for example first order logic. Our approach is to prove such properties with methods of automated reasoning after transforming the SDL specification into a first order logic specification. The proofs are done with the program verification system Tatzelwurm, especially with its prover. Practical experience shows that it is convenient to do a proof in two steps. In the first step the behaviour of the system is calculated out of the behaviour of the agents. The proofs of this step is independent of the property to prove. In this report we give a proof methods containing instructions how the arguments are applied during these proofs. It is shown how reachability analysis is done during a formal proof and how fairness arguments are applied. The report contains two papers, where the first one describes the formal basis of the method and shows the proof obligations occurring verifying a communication protocol. The second paper shows how some tedious tasks can be done more elegant using rewrite rules and recursive equations. In the appendix we give two examples out of the verification of the Abracadabra Protocol

Slicing approach to specification for testability in LOTOS

Ankara : Department of Computer Engineering and Information Science and Institute of Engineering and Science, Bilkent Univ., 1993.Thesis (Master's) -- Bilkent University, 1993.Includes bibliographical references leaves 119-123With the recent increase in the use of formal methods in specification of communication protocols, there is a need to base the conformance testing of protocol implementations on formal specifications. This brings in the problem of finding out special design issues to be used in the specification of such systems that facilitate test generation. This aspect is called Specification For Testability, and it is investigated in this study for the particular formal description technique LOTOS. Specification for testability is approached from the perspective of designing formal base protocol specifications, and then deriving functional specifications from base specifications in order to use in test generation. The method utilized for the derivation of functional specifications is Ccdled slicing. As inspired from previous work in software engineering, slices of protocol specifications are obtained systematically according to the hierarchically designed test suite structures, where each slice corresponds to a particular tunction of the protocol, and subsequent test generation is based on the obtained slices. The techni(|ues developed are demonstrated on the simple state-oriented specifications of INRES and ACSE protocols along with a real base specification of the OSI Transport Protocol written in the constraintoriented specification style. The results indicate that tests derived from functional specifications have some remarkable properties with respect to test case analysis and representation.Ateş, Ahmet FeyziM.S

User-friendly Formal Methods for Security-aware Applications and Protocols

Formal support in the design and implementation of security-aware applications increases the assurance in the final artifact. Formal methods techniques work by setting a model that unambiguously defines attacker capabilities, protocol parties behavior, and expected security properties. Rigorous reasoning can be done on the model about the interaction of the external attacker with the protocol parties, assessing whether the security properties hold or not. Unfortunately, formal verification requires a high level of expertise to be used properly and, in complex systems, the model analysis requires an amount of resources (memory and time) that are not available with current technologies. The aim of this thesis is to propose new interfaces and methodologies that facilitate the usage of formal verification techniques applied to security-aware protocols and distributed applications. In particular, this thesis presents: (i) Spi2JavaGUI, a framework for the model-driven development of security protocols, that combines (for the first time in literature) an intuitive user interface, automated formal verification and code generation; (ii) a new methodology that enables the model-driven development and the automated formal analysis of distributed applications, which requires less resources and formal verification knowledge to complete the verification process, when compared to previous approaches; (iii) the formal verification of handover procedures defined by the Long Term Evolution (LTE) standard for mobile communication networks, including the results and all the translation rules from specification documents to formal models, that facilitates the application of formal verification to other parts of the standard in the future

Petri net modelling of a communications protocol

The Petri net is a formal modelling tool applicable to distributed systems and communication protocols. Two methods of analysis are applied to formal models of the "Alternating Bit Protocol". (i) A timed Petri net model is simulated to measure protocol performance. (ii) A modular numeric Petri net model is validated by reachability analysis. The simulation and validation tools are programmed in (i) "C" language and (ii) Prolog. A specification language "Needle" is developed. It describes the model system as a hierarchy of modular state transition networks. The model is searched for all possible event sequences, and the result displayed as a reachability tree. The specification language is capable of describing models which execute backwards in simulation time. The modular numeric Petri net is the basis of a powerful computer architecture, capable of parsing its own specification language to build complex models. Attention is drawn to the similarities between Petri net theory and quantum mechanics

Applying Formal Methods to Networking: Theory, Techniques and Applications

Despite its great importance, modern network infrastructure is remarkable for the lack of rigor in its engineering. The Internet which began as a research experiment was never designed to handle the users and applications it hosts today. The lack of formalization of the Internet architecture meant limited abstractions and modularity, especially for the control and management planes, thus requiring for every new need a new protocol built from scratch. This led to an unwieldy ossified Internet architecture resistant to any attempts at formal verification, and an Internet culture where expediency and pragmatism are favored over formal correctness. Fortunately, recent work in the space of clean slate Internet design---especially, the software defined networking (SDN) paradigm---offers the Internet community another chance to develop the right kind of architecture and abstractions. This has also led to a great resurgence in interest of applying formal methods to specification, verification, and synthesis of networking protocols and applications. In this paper, we present a self-contained tutorial of the formidable amount of work that has been done in formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial

Programming with Quantum Communication

This work develops a formal framework for specifying, implementing, and analysing quantum communication protocols. We provide tools for developing simple proofs and analysing programs which involve communication, both via quantum channels and exhibiting the LOCC (local operations, classical communication) paradigm