Abstract State Machines 1988-1998: Commented ASM Bibliography

An annotated bibliography of papers which deal with or use Abstract State Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm

Quo Vadis Abstract State Machines? J.UCS Special Issue

In introducing this special ASM issue of J.UCS we point out the particular role this Journal played in the short history of the ASM method and add some reflections on its current status

Soft Constraint Programming to Analysing Security Protocols

Security protocols stipulate how the remote principals of a computer network should interact in order to obtain specific security goals. The crucial goals of confidentiality and authentication may be achieved in various forms, each of different strength. Using soft (rather than crisp) constraints, we develop a uniform formal notion for the two goals. They are no longer formalised as mere yes/no properties as in the existing literature, but gain an extra parameter, the security level. For example, different messages can enjoy different levels of confidentiality, or a principal can achieve different levels of authentication with different principals. The goals are formalised within a general framework for protocol analysis that is amenable to mechanisation by model checking. Following the application of the framework to analysing the asymmetric Needham-Schroeder protocol, we have recently discovered a new attack on that protocol as a form of retaliation by principals who have been attacked previously. Having commented on that attack, we then demonstrate the framework on a bigger, largely deployed protocol consisting of three phases, Kerberos.Comment: 29 pages, To appear in Theory and Practice of Logic Programming (TPLP) Paper for Special Issue (Verification and Computational Logic

Soft Constraint Programming to Analysing Security Protocols

Security protocols stipulate how remote principals of a computer network should interact in order to obtain specific security goals. The crucial goals of confidentiality and authentication may be achieved in various forms. Using soft (rather than crisp) constraints, we develop a uniform formal notion for the two goals. They are no longer formalised as mere yes/no properties as in the existing literature, but gain an extra parameter, the security level. For example, different messages can enjoy different levels of confidentiality, or a principal can achieve different levels of authentication with different principals. The goals are formalised within a general framework for protocol analysis that is amenable to mechanisation by model checking. Following the application of the framework to analysing the asymmetric Needham- Schroeder protocol, we have recently discovered a new attack on that protocol. We briefly describe that attack, and demonstrate the framework on a bigger, largely deployed protocol consisting of three phases, Kerberos

A Formal Analysis of Some Properties of Kerberos 5 Using MSR

We give three formalizations of the Kerberos 5 authentication protocol in the Multi-Set Rewriting (MSR) formalism. One is a high-level formalization containing just enough detail to prove authentication and confidentiality properties of the protocol. A second formalization refines this by adding a variety of protocol options; we similarly refine proofs of properties in the first formalization to prove properties of the second formalization. Our third formalization adds timestamps to the first formalization but has not been analyzed extensively. The various proofs make use of rank and corank functions, inspired by work of Schneider in CSP, and provide examples of reasoning about real-world protocols in MSR.We also note some potentially curious protocol behavior; given our positive results, this does not compromise the security of the protocol

Using kerberos for enterprise cloud authentication

The Kerberos authentication protocol has a maturity of approximately thirty years, being widely used in IT systems in the corporate environment, mainly due to its adoption by Microsoft in its operating systems. Moreover, the practical application of the Cloud computing and its concepts is in its early days regarding its adoption by organizations, especially the large companies. This study aims to investigate the practical applications of the Kerberos protocol for authentication of enterprise applications deployed in the cloud, looking from both the f unctional and security perspective. To achieve this goal, it will be necessary to evaluate its applicability to the Cloud and assess whether it keeps the security characteristics found when using it only inside the corporate network.O protocolo de autenticação Kerberos apresenta uma maturidade de aproximadamente trinta anos, sendo amplamente utilizado nos sistemas de TI no meio corporativo, principalmente devido à sua adopção pela Microsoft nos seus sistemas operativos. Por outro lado, a aplicação prática dos conceitos de computação na nuvem encontra-se nos seus primeiros passos no que diz respeito à adopção pelas empresas, principalmente as de grande porte. Este estudo propõe-se a investigar as possibilidades práticas do protocolo Kerberos para autenticação de aplicações corporativas implementadas na nuvem, do ponto de vista funcional e de segurança. Para alcançar esse objectivo, será necessário avaliar sua aplicabilidade à nuvem e fazer um levantamento para validar se o protocolo mantêm as características de segurança encontrada quando utilizado somente na rede corporativa

Formal Analysis of the Kerberos Authentication System

The Gurevich's Abstract State Machine formalism is used to specify the well known Kerberos Authentication System based on the Needham-Schroeder authentication protocol. A complete model of the system is reached through stepwise refinements of ASMs, and is used as a basis both to discover the minimum assumptions to guarantee the correctness of the system and to analyse its security weaknesses. Each refined model comes together with a correctness refinement theorem