S.W. Smith
Secure Distributed Time for Secure Distributed
Protocols
Technical Report CMU-CS-94-177,
Department of Computer Science, Carnegie Mellon University
September 1994.
Ph.D. thesis. Advisor: Doug Tygar.
This thesis addresses these issues of time and security by constructing a distributed time formalism that supports hierarchies of general time models, and then constructing clock primitives---the Signed Vector Timestamp protocol and the Sealed Vector Timestamp protocol---that provide security and privacy. Framing application problems in terms of this distributed time framework grants insight that often allows us to build protocols more general and flexible than were previously possible. Separating clocks from protocols grants additional flexibility by allowing us to keep their design issues mutually transparent.
This thesis explores three applications of this secure distributed time framework. We transparently add security and privacy to immediate ordered service protocols. We build basic distributed snapshot protocols and transparently add security, privacy, and increased flexibility. Finally, we use the framework to build a new optimistic rollback recovery protocol that substantially improves on previous work by providing full asynchrony while also reducing the worst-case bound for rollbacks after a failure from exponential to one per process; further, developing this protocol within the distributed time framework transparently allows for security and privacy.
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