Title:		Quantitative Trust Management: QuanTM, Reputation, and PreSTA

Presenter:	Andrew G. West

Date/Location:	11/18/2009 3PM, Levine 512

Abstract:	Quantitative Trust Management (QTM) provides a dynamic
interpretation of authorization policies for access control based on the
evolving reputations of those involved. In this talk, we discuss QuanTM, a
QTM system (developed at Penn) that selectively combines elements from trust
management and reputation management to create a novel method for policy
evaluation. QuanTM permits flexibility in handling situations of incomplete
trust, while still enforcing security guarantees.

A major component of the QuanTM model is the `reputation manager,' which
aggregates feedback histories into quantitative values. We briefly outline
reputation algorithms in the literature (EigenTrust, Subjective Logic), before
introducing our own effort, Preventative Spatio-Temporal Aggregation (PresTA).
PreSTA is particularly applicable to the QuanTM model due to its incorporation
of authorization hierarchies in reputation calculation. Further, the PreSTA
model has been shown effective in network-level spam filtration -- a step
towards a complete QTM use-case.