A high performance UCON and semantic-based authorization framework for grid computing

Authorization infrastructures are an important and integral part of grid computing which facilitate access control functions to protect resources.This paper presents an authorization framework that combines the usage control (UCON) model with semantic web technology.To our knowledge, an authorization framework that combines both the UCON and semantic web technology in one framework has not yet been previously proposed.As the UCON model combines traditional access control, trust management and digital rights management in a grid authorization infrastructure, its adoption enhances the capability of the authorization. However, UCON-based authorization presents a problem in controlling the policy granularity and minimizing the authorization overhead due to complexity in the policies inherited from the UCON model.The growing number of users and resources in the grid makes this problem even worse.We use the semantic web technology to provide a way to automatically manage the rules in the policies, hence keeping the granularity under control. To minimize the authorization overhead, a new mechanism to reduce the number of policy checks is proposed in this paper. Our simulation result shows that the proposed mechanism provides a 63% reduction in rule checking compared to previous methods

Access and Usage Control in Grid

Grid is a computational environment where heterogeneous resources are virtualized and outsourced to multiple users across the Internet. The increasing popularity of the resources visualization is explained by the emerging suitability of such technology for automated execution of heavy parts of business and research processes. Efficient and flexible framework for the access and usage control over Grid resources is a prominent challenge. The primary objective of this thesis is to design the novel access and usage control model providing the fine-grained and continuous control over computational Grid resources. The approach takes into account peculiarities of Grid: service-oriented architecture, long-lived interactions, heterogeneity and distribution of resources, openness and high dynamics. We tackle the access and usage control problem in Grid by Usage CONtrol (UCON) model, which presents the continuity of control and mutability of authorization information used to make access decisions. Authorization information is formed by attributes of the resource requestor, the resource provider and the environment where the system operates. Our access and usage control model is considered on three levels of abstraction: policy, enforcement and implementation. The policy level introduces security policies designed to specify the desired granularity of control: coarse-grained policies that manages access and usage of Grid services, and fine-grained policies that monitor the usage of underlying resources allocated for a particular Grid service instance. We introduce U-XACML and exploit POLPA policy languages to specify and formalize security policies. Next, the policy level presents attribute management models. Trust negotiations are applied to collect a set of attributes needed to produce access decisions. In case of mutable attributes, a risk-aware access and usage control model is given to approximate the continuous control and timely acquisition of fresh attribute values. The enforcement level presents the architecture of the state-full reference monitor designed to enforce security policies on coarse- and fine-grained levels of control. The implementation level presents a proof-of-concept realization of our access and usage control model in Globus Toolkit, the most widely used middleware to setup computational Grids

On Usage Control for Data Grids: Models, Architectures, and Specifications

This thesis reasons on usage control in Data Grids, by presenting models, architectures and specifications. This work is a step toward a continuous monitoring and control of the data access and usage in a Data Grid. First, the thesis presents a background on Grids, security, and security for Grids, by making an abstraction to the current Grid implementations. We argue that usage control in Data Grids should be considered as a process composed by two black boxes. We analysed the requirements for Grid security, and propose a distributed usage control model suitable for Grids and distributed systems alike. Then, we apply such model to a Data Grid abstraction, and present a usage control architecture for Data Grids that uses the functional components of the currents Grids. We also present an abstract specification for an enforcing mechanism for usage control policies. To do so, we use a formal requirement engineering methodology with a bottom-up approach, that proves that the specification is sound and complete. With the methodology, we show formally that such abstract specification can enforce all the different typologies of usage control policies. Finally, we consider how existing prototypes can fit in the proposed architecture, and the advantages derived from using Semantic Grid techologies for the specification of policies subjects and objects

On Usage Control for GRID Systems

This paper introduces a formal model, an architecture and a prototype implementation for usage control on GRID systems. The usage control model (UCON) is a new access control paradigm proposed by Park and Sandhu that encompasses and extends several existing models (e.g. MAC, DAC, Bell-Lapadula, RBAC, etc). Its main novelty is based on continuity of the access monitoring and mutability of attributes of subjects and objects. We identified this model as a perfect candidate for managing access/usage control in GRID systems due to their peculiarities, where continuity of control is a central issue. Here we adapt the original UCON model to develop a full model for usage control in GRID systems. We use as policy specification language a process description language and show how this is suitable to model the usage policy models of the original UCON model. We also describe a possible architecture to implement the usage control model. Moreover, we describe a prototype implementation for usage control of GRID computational services, and we show how our language can be used to define a security policy that regulates the usage of network communications to protect the local computational service from the applications that are executed on behalf of remote GRID users

A Decentralized Solution for Combinatorial Testing of Access Control Engine

In distributed environments, information security is a key factor and access control is an important means to guarantee confidentiality of sensitive and valuable data. In this paper, we introduce a new decentralized framework for testing of XACML-based access control engines. The proposed framework is composed of different web services and provides the following functionalities: I) generation of test cases based on combinatorial testing strategies; ii) decentralized oracle that associates the expected result to a given test case, i.e. an XACML request; and finally, iii) a GUI for interacting with the framework and providing some analysis about the expected results. A first validation confirms the efficiency of the proposed approach

Constraints and Strategies for the Development of the Seed System in Mozambique

Ministry of Agriculture and Rural Development, Directorate of Economics, Republic of Mozambiquefood security, food policy, Mozambique, seed system, Crop Production/Industries, Q18,

A Natural Language Programming Approach for Requirements-based Security Testing

To facilitate communication among stakeholders, software security requirements are typically written in natural language and capture both positive requirements (i.e., what the system is supposed to do to ensure security) and negative requirements (i.e., undesirable behavior undermining security). In this paper, we tackle the problem of automatically generat- ing executable security test cases from security requirements in natural language (NL). More precisely, since existing approaches for the generation of test cases from NL requirements verify only positive requirements, we focus on the problem of generating test cases from negative requirements. We propose, apply and assess Misuse Case Programming (MCP), an approach that automatically generates security test cases from misuse case specifications (i.e., use case specifications capturing the behavior of malicious users). MCP relies on natural language processing techniques to extract the concepts (e.g., inputs and activities) appearing in requirements specifications and generates executable test cases by matching the extracted concepts to the members of a provided test driver API. MCP has been evaluated in an industrial case study, which provides initial evidence of the feasibility and benefits of the approach