Biblio

Security mechanism of the mobile agent running platform is very important for mobile agent system operation and stability running. In this paper we mainly focus on the security issues related with the mobile agent running platform and we proposed a cross validation mechanism mixed with encryption algorithm to solve the security problems during the migration and communication of mobile agents. Firstly, we employ the cross-validation mechanism to authenticate the nodes mobile agents will be visiting. Secondly, we employ the hybrid encryption mechanism, which combines the advantages of the symmetric encryption and asymmetric encryption, to encrypt the mobile agents and ensure the transferring process of data. Finally, we employ the EMSSL socket communication method to encrypt the content of transmission, in turn to enhance the security and robustness of the mobile agent system. We implement several experiments in the simulation environment and the experimental results verify the efficiency and accuracy of the proposed methods.

Network architectures and applications are becoming increasingly complex. Several approaches to automatically enforce configurations on devices, applications and services have been proposed, such as Policy-Based Network Management (PBNM). However, the management of enforced configurations in production environments (e.g. data center) is a crucial and complex task. For example, updates on firewall configuration to change a set of rules. Although this task is fundamental for complex systems, few effective solutions have been proposed for monitoring and managing enforced configurations. This work proposes a novel approach to monitor and manage enforced configurations in production environments. The main contributions of this paper are a formal model to identify/ generate traffic flows and to verify the enforced configurations; and a slim and transparent framework to perform the policy assessment. We have implemented and validated our approach in a virtual environment in order to evaluate different scenarios. The results demonstrate that the prototype is effective and has good performance, therefore our model can be effectively used to analyse several types of IT infrastructures. A further interesting result is that our approach is complementary to PBNM.

Cloud service providers typically adopt the multi-tenancy model to optimize resources usage and achieve the promised cost-effectiveness. Sharing resources between different tenants and the underlying complex technology increase the necessity of transparency and accountability. In this regard, auditing security compliance of the provider's infrastructure against standards, regulations and customers' policies takes on an increasing importance in the cloud to boost the trust between the stakeholders. However, virtualization and scalability make compliance verification challenging. In this work, we propose an automated framework that allows auditing the cloud infrastructure from the structural point of view while focusing on virtualization-related security properties and consistency between multiple control layers. Furthermore, to show the feasibility of our approach, we integrate our auditing system into OpenStack, one of the most used cloud infrastructure management systems. To show the scalability and validity of our framework, we present our experimental results on assessing several properties related to auditing inter-layer consistency, virtual machines co-residence, and virtual resources isolation.

Resiliency is a relatively new topic in the context of access control. Informally, it refers to the extent to which a multi-user computer system, subject to an authorization policy, is able to continue functioning if a number of authorized users are unavailable. Several interesting problems connected to resiliency were introduced by Li, Wang and Tripunitara [13], many of which were found to be intractable. In this paper, we show that these resiliency problems have unexpected connections with the workflow satisfiability problem (WSP). In particular, we show that an instance of the resiliency checking problem (RCP) may be reduced to an instance of WSP. We then demonstrate that recent advances in our understanding of WSP enable us to develop fixed-parameter tractable algorithms for RCP. Moreover, these algorithms are likely to be useful in practice, given recent experimental work demonstrating the advantages of bespoke algorithms to solve WSP. We also generalize RCP in several different ways, showing in each case how to adapt the reduction to WSP. Li et al also showed that the coexistence of resiliency policies and static separation-of-duty policies gives rise to further interesting questions. We show how our reduction of RCP to WSP may be extended to solve these problems as well and establish that they are also fixed-parameter tractable.

Dynamic taint analysis can be used as a defense against low-integrity data in applications with untrusted user interfaces. An important example is defense against XSS and injection attacks in programs with web interfaces. Data sanitization is commonly used in this context, and can be treated as a precondition for endorsement in a dynamic integrity taint analysis. However, sanitization is often incomplete in practice. We develop a model of dynamic integrity taint analysis for Java that addresses imperfect sanitization with an in-depth approach. To avoid false positives, results of sanitization are endorsed for access control (aka prospective security), but are tracked and logged for auditing and accountability (aka retrospective security). We show how this heterogeneous prospective/retrospective mechanism can be specified as a uniform policy, separate from code. We then use this policy to establish correctness conditions for a program rewriting algorithm that instruments code for the analysis. The rewriting itself is a model of existing, efficient Java taint analysis tools.

Recent literature on iOS security has focused on the malicious potential of third-party applications, demonstrating how developers can bypass application vetting and code-level protections. In addition to these protections, iOS uses a generic sandbox profile called "container" to confine malicious or exploited third-party applications. In this paper, we present the first systematic analysis of the iOS container sandbox profile. We propose the SandScout framework to extract, decompile, formally model, and analyze iOS sandbox profiles as logic-based programs. We use our Prolog-based queries to evaluate file-based security properties of the container sandbox profile for iOS 9.0.2 and discover seven classes of exploitable vulnerabilities. These attacks affect non-jailbroken devices running later versions of iOS. We are working with Apple to resolve these attacks, and we expect that SandScout will play a significant role in the development of sandbox profiles for future versions of iOS.