A pay television satellite broadcast includes validation data that can be used to validate authenticity of live global positioning system (GPS) data. The validation data may be included within entitlement messages and encrypted for security and selective reception by authorized receivers. A navigation system may compute checksums of received live GPS data and compare with the validation data for a match. A decision about whether or not to use the live GPS data may be taken based on whether or not the computed checksums match the validation data received via the pay television satellite broadcast signals.