Development and evaluation of a fault-tolerant multiprocessor (FTMP) computer. Volume 4: FTMP executive summary

The FTMP architecture is a high reliability computer concept modeled after a homogeneous multiprocessor architecture. Elements of the FTMP are operated in tight synchronism with one another and hardware fault-detection and fault-masking is provided which is transparent to the software. Operating system design and user software design is thus greatly simplified. Performance of the FTMP is also comparable to that of a simplex equivalent due to the efficiency of fault handling hardware. The FTMP project constructed an engineering module of the FTMP, programmed the machine and extensively tested the architecture through fault injection and other stress testing. This testing confirmed the soundness of the FTMP concepts

Combining High-Level and Low-Level Approaches to Evaluate Software Implementations Robustness Against Multiple Fault Injection Attacks

International audiencePhysical fault injections break security functionalities of algorithms by targeting their implementations. Software techniques strengthen such implementations to enhance their robustness against fault attacks. Exhaustively testing physical fault injections is time consuming and requires complex platforms. Simulation solutions are developed for this specific purpose. We chose two independent tools presented in 2014, the Laser Attack Robustness (Lazart) and the Embedded Fault Simulator (EFS) in order to evaluate software implementations against multiple fault injection attacks. Lazart and the EFS share the common goal that consists in detecting vulnerabilities in the code. However, they operate with different techniques , fault models and abstraction levels. This paper aims at exhibiting specific advantages of both approaches and proposes a combining scheme that emphasizes their complementary nature

Modular Injection System and Sampling Template (M.I.S.S.T) Design Report

Digital systems are ubiquitous throughout modern life and their applications continue to grow. Thus system designers engineer and test modular systems to mitigate error rates. Smaller systems and their increasing importance in many applications demand the utmost reliability. Fault injection is the most common method used by researchers and engineers to test system reliability. However, most hardware fault injection implementations are ad hoc and only used to test a specific system or for specific tests. There is also software-implemented fault injection that adds overhead in the benchmark source code. The aim of this project is to develop a general use, fault injection hardware module that can be integrated into a digital system. This module would be easy to use and flexible for most reliability testing. This document explains the design of such a system

Fault injection testing of software implemented fault tolerance mechanisms of distributed systems

PhD ThesisOne way of gaining confidence in the adequacy of fault tolerance mechanisms of a system is to test the system by injecting faults and see how the system performs under faulty conditions. This thesis investigates the issues of testing software-implemented fault tolerance mechanisms of distributed systems through fault injection. A fault injection method has been developed. The method requires that the target software system be structured as a collection of objects interacting via messages. This enables easy insertion of fault injection objects into the target system to emulate incorrect behaviour of faulty processors by manipulating messages. This approach allows one to inject specific classes of faults while not requiring any significant changes to the target system. The method differs from the previous work in that it exploits an object oriented approach of software implementation to support the injection of specific classes of faults at the system level. The proposed fault injection method has been applied to test software-implemented reliable node systems: a TMR (triple modular redundant) node and a fail-silent node. The nodes have integrated fault tolerance mechanisms and are expected to exhibit certain behaviour in the presence of a failure. The thesis describes how various such mechanisms (for example, clock synchronisation protocol, and atomic broadcast protocol) were tested. The testing revealed flaws in implementation that had not been discovered before, thereby demonstrating the usefulness of the method. Application of the approach to other distributed systems is also described in the thesis.CEC ESPRIT programme, UK Engineering and Physical Sciences Research Council (EPSRC)

Systematic Model-based Design Assurance and Property-based Fault Injection for Safety Critical Digital Systems

With advances in sensing, wireless communications, computing, control, and automation technologies, we are witnessing the rapid uptake of Cyber-Physical Systems across many applications including connected vehicles, healthcare, energy, manufacturing, smart homes etc. Many of these applications are safety-critical in nature and they depend on the correct and safe execution of software and hardware that are intrinsically subject to faults. These faults can be design faults (Software Faults, Specification faults, etc.) or physically occurring faults (hardware failures, Single-event-upsets, etc.). Both types of faults must be addressed during the design and development of these critical systems. Several safety-critical industries have widely adopted Model-Based Engineering paradigms to manage the design assurance processes of these complex CPSs. This thesis studies the application of IEC 61508 compliant model-based design assurance methodology on a representative safety-critical digital architecture targeted for the Nuclear power generation facilities. The study presents detailed experiences and results to demonstrate the benefits of Model testing in finding design flaws and its relevance to subsequent verification steps in the workflow. Additionally, to study the impact of physical faults on the digital architecture we develop a novel property-based fault injection method that overcomes few deficiencies of traditional fault injection methods. The model-based fault injection approach presented here guarantees high efficiency and near-exhaustive input/state/fault space coverage, by utilizing formal model checking principles to identify fault activation conditions and prove the fault tolerance features. The fault injection framework facilitates automated integration of fault saboteurs throughout the model to enable exhaustive fault location coverage in the model

How Aerospace and Transportation Design Challenges can be addressed from Simulation-based Virtual Prototyping for Distributed Safety Critical Automotive Applications

International audienceThe reduction of development and product costs for distributed and software dominated safety-critical automotive applications can only be achieved via novel methodologies and tool sets that address fault injection/analysis and integration testing via simulation-based virtual prototyping. In fact, earlier discovery of design errors and initial proof of safety in critical conditions should be addressed earlier using a system virtual prototype, before hardware and software implementations are available. In this paper, we propose a methodology that allows evaluating fault-tolerant system architectures in the presence of errors caused by faults of hardware elements or interferences. We illustrate how the paradigm shift from physical to virtual integration platforms can be applied to Aerospace and Transportation domains effectively