End-to-end security in service-oriented architecture

A service-oriented architecture (SOA)-based application is composed of a number of distributed and loosely-coupled web services, which are orchestrated to accomplish a more complex functionality. Any of these web services is able to invoke other web services to offload part of its functionality. The main security challenge in SOA is that we cannot trust the participating web services in a service composition to behave as expected all the time. In addition, the chain of services involved in an end-to-end service invocation may not be visible to the clients. As a result, any violation of client’s policies could remain undetected. To address these challenges in SOA, we proposed the following contributions. First, we devised two composite trust schemes by using graph abstraction to quantitatively maintain the trust levels of different services. The composite trust values are based on feedbacks from the actual execution of services, and the structure of the SOA application. To maintain the dynamic trust, we designed the trust manager, which is a trusted-third party service. Second, we developed an end-to-end inter-service policy monitoring and enforcement framework (PME framework), which is able to dynamically inspect the interactions between services at runtime and react to the potentially malicious activities according to the client’s policies. Third, we designed an intra-service policy monitoring and enforcement framework based on taint analysis mechanism to monitor the information flow within services and prevent information disclosure incidents. Fourth, we proposed an adaptive and secure service composition engine (ASSC), which takes advantage of an efficient heuristic algorithm to generate optimal service compositions in SOA. The service compositions generated by ASSC maximize the trustworthiness of the selected services while meeting the predefined QoS constraints. Finally, we have extensively studied the correctness and performance of the proposed security measures based on a realistic SOA case study. All experimental studies validated the practicality and effectiveness of the presented solutions

Privacy-Aware Location-Aided Routing in Mobile Ad Hoc Networks

Mobile Ad-hoc Networks (MANETs) enable users in physical proximity to each other to exchange data without the need for expensive communication infrastructures. Each user represents a node in the network, and executes a neighbor discovery Typically, nodes broadcast beacon messages that are received by other participants within the sender’s communication range. Routing strategies are computed on-line based on the locations of nearby nodes, and geocasting is employed to deliver data packets to their destinations. However, mobile users may be reluctant to share their exact locations with other participants, since location can disclose private details about a person’s lifestyle, religious or political affiliations, etc. A common approach to protect location privacy is to replace exact coordinates with coarser-grained regions, based on the privacy profile of each user. In this paper, we investigate protocols that support MANET routing without disclosing exact positions of nodes. Each node defines its own privacy profile, and reports a cloaked location information to its neighbors. We adopt a novel strategy to advertise beacons, to prevent inference of node locations. We also propose packet forwarding heuristics that rely on cloaking regions, rather than point locations. Our extensive experimental evaluation shows that the proposed routing scheme achieves low delays and high packet delivery ratios, without incurring significant overhead compared to conventional MANET routing protocols

An End-to-End Security Auditing Approach for Service Oriented Architectures

Service-Oriented Architecture (SOA) is becoming a major paradigm for distributed application development in the recent explosion of Internet services and cloud computing. However, SOA introduces new security challenges not present in the single-hop client-server architectures due to the involvement of multiple service providers in a service request. The interactions of independent service domains in SOA could violate service policies or SLAs. In addition, users in SOA systems have no control on what happens in the chain of service invocations. Although the establishment of trust across all involved partners is required as a prerequisite to ensure secure interactions, still a new end-to-end security auditing mechanism is needed to verify the actual service invocations and its conformance to the expected service orchestration. In this paper, we provide an efficient solution for end-to-end security auditing in SOA. The proposed security architecture introduces two new components called taint analysis and trust broker in addition to taking advantages of WS-Security and WS-Trust standards. The interaction of these components maintains session auditing and dynamic trust among services. This solution is transparent to the services, which allows auditing of legacy services without modification. Moreover, we have implemented a prototype of the proposed approach and verified its effectiveness in a LAN setting and the Amazon EC2 cloud computing infrastructure