Stabilizing Trust and Reputation for Self-Stabilizing Efficient Hosts in Spite of Byzantine Guests (Extended Abstract)

Abstract

This work presents a general and complete method to protect a system against possible malicious programs. We provide concepts for building a system that can automatically recover from an arbitrary state including even one in which a Byzantine execution of one or more programs repeatedly attempts to corrupt the system state. Preservation of a guest execution is guaranteed as long as the guest respects a predefined contract, while efficiency is improved by using stabilizing reputation. We augment a provable self-stabilizing host operating system implementation with a contract-enforcement framework example.

Feasibility of Stepwise Design of Multitolerant Programs

“…Most existing approaches [Anagnostou 1993;Arora and Kulkarni 1998a;Dolev and Herman 1995;Dolev and Yagel 2007;Dolev and Hoch 2007a;Malekpour 2006;1:4 A. Ebnenasir and S. S. Kulkarni Tsang and Magill 1994] for the design of multitolerant programs are based on a design-and-verification method, where algorithms that tolerate multiple classes of faults are designed first and then verified to ensure correctness. The verification task is often difficult and expensive as one must mechanically prove that (i) in the absence of faults, the multitolerant program satisfies its safety and liveness; (ii) in the presence of each individual class of faults the multitolerant program provides a required level of fault tolerance; (iii) each level of fault tolerance designed for tolerating a specific fault-class does not interfere with the normal functionalities in the absence of faults; and more importantly, (iv) the fault tolerance functionalities designed for each fault-class do not interfere with the functionalities designed for other levels of fault tolerance.…”