Dynamic Verification of Operating System Decisions Dynamic verification of a decision implies that every time the decision is made there is a consistency check performed on the decision using independent hardware and software. The dynamic verification of operating system decisions is used on the PRIME system being designed and constructed at the University of California, Berkeley. PRIME is an experimental time-sharing which is to have the properties of continuous availability, data privacy, and cost effectiveness. The technique of dynamic verification allows the construction of an operating system which does not make certain decisions improperly even in the presence of a single hardware or software fault. Furthermore, multiple faults lead to unreliable operation only if the faults happen to reinforce each other. On PRIME, dynamic verification is used to ensure that one user's information cannot become available to another user gratuitously even in the presence of a single hardware or software fault.the amount of additional hardware and software required for dynamic verification can be modest. CACM November, 1973 Fabry, R. S. operating systems, data security, fault tolerance, software reliability, data privacy, program verification, modular computer systems 4.32 CA731102 JB January 20, 1978 10:56 AM 1828 4 2424 1854 4 2424 1877 4 2424 1960 4 2424 2150 4 2424 2317 4 2424 2319 4 2424 2377 4 2424 2342 4 2424 2376 4 2424 2379 4 2424 2424 4 2424 2482 4 2424 2618 4 2424 2632 4 2424 2704 4 2424 2723 4 2424 2738 4 2424 2740 4 2424 2741 4 2424 2867 4 2424 3184 4 2424 1749 5 2424 2424 5 2424 2424 5 2424 2424 5 2424