Secure Refinement
Abstract
The confidentiality of information in multi level secure systems is maintained by sanitizing requests for information according to the requester's clearance. However information can flow indirectly through subtle modulations of shared resources -- so-called signaling channels. These channels can be avoided in specifying secure systems, but as a system specification is progressively refined in the design process, extraneous behaviours can easily be introduced, opening up more and more signalling channels. The process of constructing a system which is free from signalling channels is therefore two-fold: firstly, show that the system specification is free from threatening signalling channels, by demonstrating its correspondence to a security policy model; secondly, prove that successive design specifications do not introduce additional signalling channels, i.e. they are 'secure refinements' of the system specification.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1991
- Accession Number
- ADA241631
Entities
People
- Paul Smith
Organizations
- Royal Signals and Radar Establishment