PoET (Proof of Elapsed Time) is a sub-protocol of NiPoST. It is the algorithm that measures time. Elapsed time is measured by iterating a sequential work cycle that takes a set amount of time to execute. The algorithm provides a proof that it has worked sequentially for a predetermined number of cycles, and thus proves that the period of time determined by its parameters has elapsed during its entire execution. PoET is not run locally by the Smesher; users query communal PoET servers. As a result, the entire network may need only a small number of PoET servers.