Title: When not all bits are equal: incorporating "worth" into
information-flow measures
Authors: Mário S. Alvim, Andre Scedrov, Fred B. Schneider
Abstract:
Approaches to quantitative information flow (QIF)
traditionally have presumed that all leaks involving a given number of
bits are equally harmful. The presumption is unrealistic, so in the
FCS workshop we will discuss our approach to the problem. Secrets are
defined in terms of fields, where derived secrets obtained by
combining these fields can be assigned a different "worth" (perhaps in
proportion to the harm that would result from disclosure). New
measures that incorporate worth into QIF are then discussed; they
generalize probability of guessing, guessing entropy, and Shannon
entropy. A lattice of information is derived to provide an underlying
algebraic structure for an adversary's state of knowledge in this
more-general setting.