Abstract: Information sharing is intrinsic to collaboration in cyber
space. Information is shared amongst participants in context of a
collaborative mission. As the collaboration evolves participants come
and go, and information is added, removed and updated. In this talk I
will describe a family of group-centric information sharing models
recently developed at UTSA's Institute for Cyber Security, and discuss
their application to collaborative systems. At an intuitive level we
use the metaphor of a secure meeting room where participants can share
information according to different policies such as a room where
information is permanently recorded and accessible to new participants
versus a room where only the current information is available. At a
formal level these policies are characterized by temporal formulas
based on the relative timings of participants and information objects
joining and leaving the collaboration.