Affiliations: [a] Department of Computer Science, ETH Zürich, CH-8092 Zürich, Switzerland | [b] Omnisec AG, Trockenloostrasse 91, CH-8105 Regensdorf, Switzerland
Note: [*] A preliminary version of this paper appeared in Proc. of the 1994 European Symposium on Research in Computer Security (ESORICS'94), D. Gollmann, ed., Lecture Notes in Computer Science, Vol. 875, Springer-Verlag, Berlin, pp. 175-192.
Abstract: A calculus of channel security properties is presented which allows the analysis and comparison of protocols for establishing secure channels in a distributed open system at a high level of abstraction. A channel is characterized by its direction, its time of availability and its security properties. Cryptographic primitives as well as trust relations are interpreted as transformations for channel security properties, and a cryptographic protocol can be viewed as a sequence of such transformations. A protocol thus allows to transform a set of secure channels established during an initial setup phase, together with a set of insecure channels available during operation of the system, into the set of secure channels specified by the security requirements. The necessary and sufficient requirements for establishing a secure channel between two entities A and B are characterized in terms of secure channels to be made available during the initial setup phase and in terms of the minimal trust A and B must have into other entities or into trusted third parties.
