Time and Probability-Based Information Flow Analysis

Abstract—In multilevel systems it is important to avoid unwanted indirect information flow from higher levels to lower levels, namely the so called covert channels. Initial studies of information flow analysis were d by abstracting away from time and probability. It is already known that systems that are proved to be secure in a possibilistic framework may turn out to be insecure when time or probability are considered. Recently, work has been done in order to consider also aspects either of time or of probability, but not both. In this paper we propose a general framework, based on Probabilistic Timed Automata, where both probabilistic and timing covert channels can be studied. We define a Non-Interference security property and a Non Deducibility on Composition security property, which allow expressing information flow in a timed and probabilistic setting. We then compare these properties with analogous ones defined in contexts where either time or probability or neither of the...

• Type: Journal
• Year: 2010
• Where: TSE
• Authors: Ruggero Lanotte, Andrea Maggiolo-Schettini, Angelo Troina
• Keywords: Covert Channels, Information flow, Security Property, TSE 2010