Jonathan A. Poritz

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The pervasive interconnection of systems throughout the world has given computer services a significant socioeconomic value that both accidental faults and malicious activity can affect. The classical approach to security has mostly consisted of trying to prevent bad things from happening-by developing systems without vulnerabilities, for example, or by(More)
The <i>Trusted Computing Group</i> (TCG) is an industry consortium which has invested in the design of a small piece of hardware (roughly a smartcard), called a <i>Trusted Platform Module</i> (TPM), and associated APIs and protocols which are supposed to help increase the reliability of TPM-endowed computing platforms (<i>trusted platforms</i>). The TCG(More)
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This document describes the designs of a generic distributed certification authority and of a trusted party for optimistic fair exchange that are based on fault-tolerant middle-ware for service replication. It also discusses other uses of the replication middleware for implementing trusted services. It may serve as a blueprint for building generic trusted(More)
The pervasive interconnection of systems all over the world has given computer services a significant socioeconomic value, which can be affected both by accidental faults and by malicious activity. It would be appealing to address both problems in a seamless manner, through a common approach to security and dependability. This is the proposal of 'intrusion(More)
I describe a new formalization for computation which is similar to traditional circuit models but which depends upon the choice of a family of [semi]groups – essentially, a choice of the structure group of the universe of the computation. Choosing the symmetric groups results in the reversible version of classical computation; the unitary groups give(More)