Pledge: a Policy-based Security Protocol for Protecting Content Addressable Storage Architectures

In this paper we present PLEDGE, an efficient and scalable security ProtocoL for protecting fixedcontent objects in contEnt aDdressable storaGe (CAS) architEctures. PLEDGE follows an end-to-end policy-driven security approach to secure the confidentiality, integrity, and authenticity of fixed-content entities over the enterprise network links and in the nodes of the CAS device. It utilizes a customizable and configurable extensible mark-up language (XML) security policy to provide flexible, multi-level, and fine-grained encryption and hashing methodologies to fixed content CAS entities. PLEDGE secures data objects based on their content and sensitivity and highly overcomes the performance of bulk and raw encryption protocols such as the Secure Socket Layer (SSL) and the Transport Layer Security (TLS) protocols. Moreover, PLEDGE transparently stores sensitive objects encrypted (partially or totally) in the CAS storage nodes without affecting the CAS storage system operation or performance and takes into consideration the processing load, computing power, and memory capabilities of the client devices which may be constrained by limited processing power, memory resources, or network connectivity. PLEDGE complies with regulations such as the Health Insurance Portability and Accountability Act (HIPAA) requirements and the SEC Rule 17a-4 financial standards. The protocol is implemented in a real CAS network using an EMC Centera backend storage device. The application secured by PLEDGE in the sample implementation is an X-Ray radiography scanning system in a healthcare network environment. The experimental test bed implementation conducted shows a speedup factor of three over raw encryption security mechanisms.