METHOD FOR ACHIEVING MULTIPLE PROCESSOR AGREEMENT OPTIMIZED FOR NO FAULTS

An originating processor broadcasts a value in a message with its unforgeable signature to all n active processors, including itself. Receiving processors in the network pass such a message on with their own unforgeable signatures to all active processors, including themselves. If the number of signatures and phases is the same at each processor after the first two successive passings, then agreement as to the value with no fault is indicated, otherwise if after two passings, (t+1) signatures have been collected, then these are signed and sent in the third passing, and in any case, each processor continues the steps of repeatedly sending messages when received, and appending its signature until t+2 passings have occurred. At that time, a processor will agree to the value if at least (t+1) signatures append the message, otherwise a default value is adopted, t (n/2) being a reliability measure.