Optimal clock synchronization?

Abstract

We present a simple, efficient and unified solution to the problems of synchronizing clocks, initializing these clocks, and integrating new clocks, for both authenticated and nonauthenticated systems with arbitrary failures. This is the first known solution that achieves optimal accuracy, i.e., the accuracy of synchronized clocks (with respect to real time) is as good as that specified for the underlying hardware clocks. The algorithms presented are also optimal with respect to the number of faulty processes that can be tolerated to achieve this accuracy.