Service Automata

We propose a novel framework for reliably enforcing security in distributed systems. Service automata monitor the execution of a distributed program and enforce countermeasures before a violation of a security policy can occur. A key novelty of our proposal is that security is enforced in a decentralized though coordinated fashion. This provides the basis for reliably enforcing global security requirements without introducing unnecessary latencies or communication overhead. The novel contributions of this article include the concept of service automata and a generic formalization of service automata in CSP. We also illustrate how the generic model can be tailored to given security requirements by instantiating its parameters in a stepwise and modular manner