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There exist many approaches to specify and to define security policies. We present here a framework in which the basic components of security policies can be expressed, and we identify their role in the description of a policy, of a system and of a secure system. In this setting, we formally describe two approaches to define policies, and we relate them: the rule-based approach consists of specifying the conditions under which an action is granted and, the property-based approach consists of specifying the security properties the policy aims to enforce. We also show how a policy can be applied to constrain an existing system, and how a secure system can be defined from a security policy. [ABSTRACT FROM AUTHOR]

Protection deals with the enforcement of integrity and confidentiality. Integrity violations often lead to confidentiality vulnerabilities. This paper proposes a novel approach of Mandatory Access Control enforcement for guaranteeing a large range of integrity properties. In the literature, many integrity models are proposed such as the Biba model, data integrity, subject integrity, domain integrity and Trusted Path Execution. There can be numerous integrity models. In practice, an administrator needs to combine various integrity models. The major limitations of existing solutions deal first with the support of indirect activities aiming at violating integrity and second with the impossibility to extend existing models or even define new ones. This paper proposes a novel framework for expressing integrity requirements associated with direct or indirect activities, mostly in terms of information flows. It presents a formalization for the major integrity properties of the literature. The formalization of the required security is efficient and a straightforward enforcement is proposed. In contrast with our previous work, an information flow graph provides a dynamic analysis of the requested properties. The paper also provides a MAC implementation that enforces every integrity property supported by our formalization. Thus, a system call fails if it could violate the required security properties. A large scale experiment on high interaction honeypots shows the relevance, robustness and efficiency of our approach. This experimentation sets up two kinds of hosts. Hosts with our solution in IDS mode detect the violation of the requested properties. That IDS allows us to verify the completeness of our MAC protection. Hosts with our MAC protection guarantee all the required properties. [ABSTRACT FROM AUTHOR]

The Unified Modeling Language UML 2.0 plays a central role in modern software engineering, and it is considered as the de facto standard for modeling software architectures and designs. Today?s systems are becoming more and more complex, and very difficult to deal with. The main difficulty arises from the different ways in modelling each component and the way they interact with each others. At this level of software modeling, providing methods and tools that allow early detection of errors is mandatory. In this paper, a verification methodology of a composition of UML behavioural diagrams (State Machine, Activity Diagram, and Sequence Diagram) is proposed. Our main contribution is the systematic construction of a semantic model based on a novel composition operator. This operator provides an elegant way to define the combination of different kind of UML diagrams. In addition, this operator posses a nice property which allows to handle the verification of large system efficiently. To demonstrate the effectiveness of our approach, a case study is presented. [ABSTRACT FROM AUTHOR]

Execution monitoring (EM) is a widely adopted class of security mechanisms. EM-enforceable security properties are usually characterized by security automata and their derivatives. However Edit automata (EA) have been recently proposed to specify more powerful EMs. Being able to feign the execution of sensitive program actions, these EMs are supposed to enforce more security properties. However, feigning program actions will usually make the program behaving in discordance with its specification since the effects of feigned actions are not reflected in the program states. In this paper we highlight this problem and show how program rewriting can be a reliable enforcement alternative. The paper contribution is mainly a semantics foundation for program rewriting enforcement of EA-enforceable security properties. [ABSTRACT FROM AUTHOR]

Mobile Agents (MAs) are not fully adopted for implementing distributed system especially in e-commerce application. The main reason is the security issues associated with use of MAs. Providing integrity of execution is considered as the most challenging problem in MAs. Mobile agent Graph Head Sealing (MAGHS) is a technique that aims towards providing integrity of execution. This paper discusses the attacks that can be launched against MAGHS technique and how the security properties for MAs data integrity are fulfilled. We try to model the behavior of a malicious host by launching a series of passive attacks against mobile agent and then see to what extent the security properties for mobile agent can be achieved. The experimental results suggest that MAGHS framework can be used to protect the computations results of mobile agents. [ABSTRACT FROM AUTHOR]