Information Flow Security for Service Compositions.

Web services are ubiquitous technologies which are used for integrating business processes and services. As is the case in many other applications, the information processed in web services might be commercially sensitive and it is important to protect this information against security threats such as disclosure to unauthorized parties. In this paper we propose a notion of non-interference for service compositions expressed as terms of a typed CCS-like process algebra. Security policies are used to specify the security requirements of service components and may be dynamically provided by the service participants. We study the conditions under which service components may be replaced in a service composition while preserving both non-interference and compliance, that is a basic property ensuring the absence of livelocks and deadlocks during execution.