US Patent 9043602 Generating and using ephemeral identifiers and message integrity codes

Systems and methods for generating and using ephemeral identifiers are provided. One example method includes determining, by one or more computing devices, a current time-count. The method includes determining, by the one or more computing devices, a time-modified identifier based at least in part on a static identifier and the current time-count. The method includes determining, by the one or more computing devices, an ephemeral identifier based at least in part on the time-modified identifier and a rotation key. One example system includes a plurality of beacon devices, at least one observing entity, and at least one verifying entity.