Abstract
Replication and redundancy techniques rely on the assumption that a majority of components are always safe and voting is used to resolve any ambiguities. This assumption may be unreasonable in the context of attacks and intrusions. An intruder could compromise any number of the available copies of a service resulting in a false sense of security. The kernel based approaches have proven to be quite effective but they cause performance impacts if any code changes are in the critical path. We provide an alternate user space mechanism consisting of process monitors by which such user space daemons can be unambiguously monitored without causing serious performance impacts. A framework that claims to provide such a feature must itself be tamper-resistant to attacks. We theoretically analyze and compare some relevant schemes and show their fallibility. We propose our own framework that is based on some simple principles of graph theory and well-founded concepts in topological fault tolerance, and show that it can not only unambiguously detect any such attacks on the services but is also very hard to subvert. We also present some preliminary results as a proof of concept.