PhD Proposal: Managing Unintended Information Flow in Distributed Replicated Object Systems

Advances in distributed replicated object systems, along with economies of scale, have made the once far-fetched idea of cloud computing commonplace. Information flow between replicas is a central issue in these systems. It affects many aspects of systems behavior, and mismanagement may lead to serious consequences, the most obvious one being compromised security. But security is not the only affected aspect, unintended information flow, when expressed in terms of update visibility, may also limit the consistency guarantees and flexibility these systems offer.
I propose the following thesis: Limiting unintended information flow makes it possible to build both decentralized and cloud-based replicated object systems with enhanced security that provide flexible, high-level consistency guarantees, regardless of the underlying storage substrate. Unintended information flow is a direct consequence of the anti-entropy protocols currently used in most common distributed replicated-object systems. My current work introduces cryptographic primitives and protocol changes sufficient to build secure anti-entropy mechanisms. I have demonstrated this aspect of my thesis by building and evaluating T.Rex, a distributed replication system that supports secure synchronization mechanisms. My proposed work will show how the current evolution of the cloud systems limits application level consistency. I will describe a new interface that will allow applications to define their own consistency semantics without being limited by the underlying storage substrate. I will design and implement Justice, a cloud-based replicated object system that implements the API's new functionality and demonstrates the feasibility of the approach through an extensive performance comparison with current systems, application benchmark suites, and existing applications
Examining Committee:
Committee Chair: - Dr. Peter Keleher
Dept. Representative - Dr. William Gasarch
Committee Member (s) - Dr. Neil Spring