Towards practical intrusion tolerant systems

In this paper, we propose a new approach for building mission-critical systems with an emphasis on intrusion tolerance. The fundamental mechanisms employed in this approach includes: (1) The separation of execution and state management, which enables the use of a single process to manage application requests, thereby reducing runtime overhead and enables highly concurrent executions. (2) The append-only logging policy, which protects the state of the system against an intrusion attack and ensures a clean state for the system to fallback on during recovery. (3) The use of acceptance testing as a way of verifying the integrity of the execution of application requests.