... Evaluation of Secure Time Synchronization Approaches We first derive the requirements for a secure time synchronization service for WSNs Secondly, we classify and evaluate existing secure time synchronization ... that the synchronization of nodes will remain precise between two successive resynchronizations We propose a secure, accurate, precise, and energyefficient time synchronization system for a WSN ... During the RATS phase, a CN needs to be active for each secure pairwise CN re -synchronization and for secure BAN re -synchronization The initial synchronization is ignored in this analysis as...