Patent ID: 6754845
Filing Date: 2004-06-22
Classification: G06F

Abstract:
A method for achieving agreement among n participating network devices to an agree-value in a network, the agreement arising out of a series of messages being sent and received by each participating network device, whereby the number t of faulty devices is less than n/3, each participating network device performing the following steps:a) broadcasting to the participating network devices an init-vote message comprising an init-vote value; b) once having received one of n valid of the init-vote messages with init-vote values from the participating network devices and a signal from a failure detector, evaluating the received init-vote values to obtain a verification-vote value whereby the verification-vote value is an evaluating function of the received init-vote values; c) broadcasting to the participating network devices a verification-vote message comprising the obtained verification-vote value; and d) once having received n of the verification-vote messages comprising the same verification-vote value, deciding the agree-value to be equal to the same verification-vote value, or having received a signal from any failure detector; e) broadcasting to the participating network devices a signed verification-vote message comprising the obtained verification-vote value and a signature; and f) once having received n-t signed verification-vote messages, performing a fallback agreement protocol with an initial value that has the simple majority of the received obtained verification-vote values.