Showing papers by "Michael Merritt published in 1991"
01 Jan 1991
TL;DR: Despite its many strengths, the Kerberos authentication system has a number of limitations and some weaknesses as mentioned in this paper, some of which are due to specifics of the MIT environment; others represent deficiencies in the protocol design.
Abstract: The Kerberos authentication system, a part of MIT's Project Athena, has been adopted by other organizations. Despite Kerberos's many strengths, it has a number of limitations and some weaknesses. Some are due to specifics of the MIT environment; others represent deficiencies in the protocol design. We discuss a number of such problems, and present solutions to some of them. We also demonstrate how special-purpose cryptographic hardware may be needed in some cases.
320 citations
26 Aug 1991
TL;DR: A way to add a notion of time to the input-output automaton model in a way that preserves these properties is described, and the result is a simple, compositional model for real-time computation that provides a convenient notation for expressing timing properties such as bounded fairness.
Abstract: In this paper, we augment the input-output automaton model in order to reason about time in concurrent systems, and we prove simple properties of this augmentation The input-output automata model is a useful model for reasoning about computation in concurrent and distributed systems because it allows fundamental properties such as fairness and compositionality to be expressed easily and naturally A unique property of the model is that systems are modeled as the composition of autonomous components This paper describes a way to add a notion of time to the model in a way that preserves these properties The result is a simple, compositional model for real-time computation that provides a convenient notation for expressing timing properties such as bounded fairness
129 citations
01 Jun 1991
TL;DR: A framework for proving the correctness of high-performance shared memories implementing relaxed consistency conditions, which relies on a classification of memory accesses into ordinary and synchronization, such that conflicting ordinary accesses are protected by synchronization.
49 citations
01 Jul 1991
TL;DR: A known impossibility result is generalized, and it is shown that results about how knowledge can be gained and lost in message passing systems also hold for shared memory systems.
Abstract: We study the relation between knowledge and space. That is, we analyze how much shared memory space is needed in order to learn certain kinds of facts. Such results are useful tools fo~ reasoning about shared memory systems. In addition we generalize a known impossibility result, and show that results about how knowledge can be gained and lost in message passing systems also hold for shared memory systems.
12 citations
07 Oct 1991
TL;DR: This work characterize those systems in which the consensus problem can be solved in the presence of faults and give bounds on the space required and describes a fast solution to the mutual exclusion problem using atomic m-register operations.
Abstract: We investigate systems where it is possible to access several shared registers in one atomic step Extending proofs in [Her91, LA87], we characterize those systems in which the consensus problem can be solved in the presence of faults and give bounds on the space required We also describe a fast solution to the mutual exclusion problem using atomic m-register operations
3 citations