Policy Verification Research Articles

A model checking-based approach for security policy verification of mobile systems

AbstractThis article describes an approach for the automated verification of mobile systems. Mobile systems are characterized by the explicit notion oflocation(e.g., sites where they run) and the ability to execute at different locations, yielding a number of security issues. To this aim, we formalize mobile systems as Labeled Kripke Structures, encapsulating the notion oflocation netthat describes the hierarchical nesting of the threads constituting the system. Then, we formalize a genericsecurity-policy specification languagethat includes rules for expressing and manipulating the code location. In contrast to many other approaches, our technique supports both access control and information flow specification. We developed a prototype framework for model checking of mobile systems. It works directly on the program code (in contrast to most traditional process-algebraic approaches that can model only limited details of mobile systems) and uses abstraction-refinement techniques, based also on location abstractions, to manage the program state space. We experimented with a number of mobile code benchmarks by verifying various security policies. The experimental results demonstrate the validity of the proposed mobile system modeling and policy specification formalisms and highlight the advantages of the model checking-based approach, which combines the validation of security properties with other checks, such as the validation of buffer overflows.

Allowing and Storing of Authorized and Unauthorized Database User According to the Policy Verification and Validation of Distributed Firewall Under the Specialized Database

Allowing and Storing of Authorized and Unauthorized Database User According to the Policy Verification and Validation of Distributed Firewall Under the Specialized Database

ActionScript bytecode verification with co-logic programming (abstract only)

A prototype security policy verification system for ActionScript binaries is presented, whose implementation leverages recent advances in co-logic programming. Our experience with co-logic programming indicates that it is an extremely useful paradigm for elegantly expressing algorithms that lie at the heart of model-checking technologies. This results in an unusually small trusted computing base, making the verification system well-suited to frameworks like certifying in-lined reference monitoring systems, which require small, light-weight verifiers. Preliminary experiments and progress are discussed.

Firewall policy verification and troubleshooting

Firewalls are important elements of enterprise security and have been the most widely adopted technology for protecting private networks. The quality of protection provided by a firewall mainly depends on the quality of its policy (i.e., configuration). However, due to the lack of tools for verifying and troubleshooting firewall policies, most firewalls on the Internet have policy errors. A firewall policy can error either create security holes that will allow malicious traffic to sneak into a private network or block legitimate traffic disrupting normal traffic, which in turn could lead to diestrous consequences. We propose a firewall verification and troubleshooting tool in this paper. Our tool takes as input a firewall policy and a given property, then outputs whether the policy satisfies the property. Furthermore, in the case that a firewall policy does not satisfy the property, our tool outputs which rules cause the verification failure. This provides firewall administrators a basis for how to fix the policy errors. Despite of the importance of verifying firewall policies and finding troublesome rules, they have not been explored in previous work. Due to the complex nature of firewall policies, designing algorithms for such a verification and troubleshooting tool is challenging. In this paper, we designed and implemented a verification and troubleshooting algorithm using decision diagrams, and tested it on both real-life firewall policies and synthetic firewall policies of large sizes. The performance of the algorithm is sufficiently high that they can practically be used in the iterative process of firewall policy design, verification, and maintenance. The firewall policy troubleshooting algorithm proposed in this paper is not limited to firewalls. Rather, they can be potentially applied to other rule-based systems as well.

Decision Procedures for a Deontic Logic Modeling Temporal Inheritance of Obligations

In nowadays applications of temporal deontic logic to the verification of security policies, an issue arises concerning the temporal inheritance of future directed obligations that have net yet been met. We investigate decision procedures for temporal deontic logics that account for this particular interaction between time and obligation.

Automated verification of access control policies using a SAT solver

Managing access control policies in modern computer systems can be challenging and error-prone. Combining multiple disparate access policies can introduce unintended consequences. In this paper, we present a formal model for specifying access to resources, a model that encompasses the semantics of the xacml access control language. From this model we define several ordering relations on access control policies that can be used to automatically verify properties of the policies. We present a tool for automatically verifying these properties by translating these ordering relations to Boolean satisfiability problems and then applying a sat solver. Our experimental results demonstrate that automated verification of xacml policies is feasible using this approach.

Towards Formal Verification of Role-Based Access Control Policies

Specifying and managing access control policies is a challenging problem. We propose to develop formal verification techniques for access control policies to improve the current state of the art of policy specification and management. In this paper, we formalize classes of security analysis problems in the context of role-based access control. We show that in general these problems are PSPACE-complete. We also study the factors that contribute to the computational complexity by considering a lattice of various subcases of the problem with different restrictions. We show that several subcases remain PSPACE-complete, several further restricted subcases are NP-complete, and identify two subcases that are solvable in polynomial time. We also discuss our experiences and findings from experimentations that use existing formal method tools, such as model checking and logic programming, for addressing these problems.

Formal Verification and Visualization of Security Policies

Verified and validated security policies are essential components of high assurance computer systems. The design and implementation of security policies are fundamental processes in the development, deployment, and maintenance of such systems. In this paper, we introduce an expert system that helps with the design and implementation of security policies. We show how Prolog is used to verify system correctness with respect to policies using a theorem prover. Managing and visualizing information in high assurance computer systems are challenging tasks. To simplify these tasks, we show how a graph-based visualization tool is used to validate policies and provide system security managers with a process that enables policy reviews and visualizes interactions between the system’s entities. The tool provides not only a representation of the formal model, but also its execution. The introduced executable model is a formal specification and knowledge representation method.

An algebraic theory of dynamic network routing

We develop a non-classic algebraic theory for the purpose of investigating the convergence properties of dynamic routing protocols. The algebraic theory can be regarded as a generalization of shortest-path routing, where the new concept of free cycle generalizes that of a positive-length cycle. A primary result then states that routing protocols always converge, though not necessarily onto optimal paths, in networks where all cycles are free. Monotonicity and isotonicity are two algebraic properties that strengthen convergence results. Monotonicity implies protocol convergence in every network, and isotonicity assures convergence onto optimal paths. A great many applications arise as particular instances of the algebraic theory. In intra-domain routing, we show that routing protocols can be made to converge to shortest and widest paths, for example, but that the composite metric of Internet Gateway Routing Protocol (IGRP) does not lead to optimal paths. The more interesting applications, however, relate to inter-domain routing and its Border Gateway Protocol (BGP), where the algebraic framework provides a mathematical template for the specification, design, and verification of routing policies. We formulate existing guidelines for inter-domain routing in algebraic terms, propose new guidelines contemplating backup relationships between domains, and derive a sufficient condition for signaling correctness of internal-BGP.

Policy Analysis and Verification by Graph Transformation Tools

Policies are used to control the behavior of large-scale systems. After policies are designed and before policies are implemented, it should be possible to analyze the policies and verify that they behave as expected. Graph transformations provide a good method to carry out the analysis and verification because of the intuitive representation of policies and the mature theory. Here, we show how graph transformations can simulate PONDER policies and use the graph tools AGG and GROOVE to do the static and dynamic analysis.

Towards secure sealing of privacy policies

In order to provide customers with a sense of security regarding the protection of their personal data, companies sign on to a “seal” programme, where rules designed by the seal issuer in accordance to underlying laws must be adhered to. A user can verify online that a specific organisation adheres to a published privacy policy. This paper argues that the verifications means these programmes use are vulnerable to DNS spoofing attacks and present a privacy policy verification (“seal”) scheme, which is not vulnerable to attack. It is also argued that there are disadvantages in operating seal schemes that attempt to publicly certify compliance levels with a self‐regulatory privacy protection model. On the contrary, these disadvantages are softened when used in a regulatory model that has adopted comprehensive laws to ensure privacy protection.

Optimisation and experimental verification of startup policies for distillation columns

Startup of distillation columns is one of the most difficult operations in the chemical industry. Since the startup often lasts a long period of time, leads to off-spec products, and costs much energy, optimisation of startup operating policies for distillation columns is of great interest. In the last few years, we have carried out both theoretical studies and experimental verifications with the purpose of minimising the startup time of distillation columns. Model-based optimisation as well as real plant implementation is the core of this work. The model is at first validated with experimental data and then used in the optimisation problem formulation. A rigorous column model and a sequential dynamic optimisation approach have been applied to several pilot distillation columns. Experimental results indicate that a significant reduction of the startup time can be achieved by implementing the developed optimal policies. These results demonstrate the applicability of the modelling and optimisation methodology.

Automatic Verification of Static Policies on Software Process Models

Software Process Technology evolved to support software processes management by assisting the modeling, enacting and evolution of complex process models. This paper presents a contribution to this field, describing a mechanism to formally model Static Policies, which are useful to automate the verification of user-defined process syntactical properties. The proposed mechanism acts during software process modeling, promoting the reuse of policy instances across different processes in a software organization. In this text, the language for Static Policy definition is presented first through its informal description, followed by examples. This paper also discusses some of the main issues related to the formal (algebraic) semantics defined for the Policy interpreter, which based the implementation of a Java-based prototype.

Control and Assurance in E-Commerce: Privacy, Integrity, and Security at eBay

Concern about privacy, integrity, and security of online transactions hampers absorption of e-commerce technologies as a normal way of doing business. To gain acceptance and trust of their participants, all organizations must achieve control or expectations equilibrium- a state where participants choose to do what others expect of them. Establishing control in e-commerce requires us to expand the traditional view of internal control to encompass the activities of customers, suppliers, and other ”outside” users of their electronic platforms. We present a framework for analyzing control in online auctions. Privacy, authentication, and denial-of-service attacks are three classes of risk especially prevalent in e-commerce. Using the control practices of eBay as an illustrative example, we suggest possible ways of controlling these risks. Privacy, integrity, and security of online transactions demand new types of assurance services in e-commerce. We analyze assurance services available in 2002 and discuss challenges and opportunities facing existing services such as WebTrust. The merits of developing proprietary versus industry standards, and simple operational verification of client-specific policies for e-commerce assurance services are also discussed.

INTEGRATED MULTI-MEDIA COMPUTERS IN THE EXECUTION OF ISO9000 QUALITY SYSTEM REQUIREMENTS FOR DOCUMENT CONTROL AND TRAINING

The current emphasis on ISO9000 Quality Systems has met with mixed reactions in both manufacturing and service organisations. Many businesses throughout the world are feeling obliged to implement these systems which rely heavily on verification of organisational policies and procedures. This has led to a proliferation of documentation which many organisations have criticised as being bureaucratic and inflexible. The current trend towards fewer levels of management hierarchy in many organisations has been inhibited by Quality Systems because the emphasis often seems to lead to a need for more approval, accountability and control mechanisms. New thinking in integrated computerised Quality Systems offers the potential to overcome many of these difficulties. To date, attempts to computerise Quality Systems have been confined to computerisation of existing systems which will never overcome their inherent limitations. This paper describes a new approach to the Document Control and Training Requirements of ISO9000 which would enable far more flexible and responsive systems. The approach is compatible with modern flat organisational structures and allows their full benefit to be realised. © 1997 Elsevier Science Ltd

Contemporary Security Policy verification: An introduction and literature survey

(1988). Contemporary Security Policy verification: An introduction and literature survey. Arms Control: Vol. 9, No. 1, pp. 38-58.

Contemporary Security Policy verification: The special case of IAEA‐NPT ‘special inspections’

(1982). Contemporary Security Policy verification: The special case of IAEA‐NPT ‘special inspections’. Arms Control: Vol. 3, The Verification of Arms Control Agreements, pp. 57-75.