The present disclosure provides a communication apparatus comprising a cryptographic circuitry which, in operation, uses a shared cryptographic secret Key and a cryptographic salt to generate a cryptographically encoded Message Integrity Code (MIC) that is computed over the address field of a Wake Up Radio (WUR) frame; and a transmission signal generator which, in operation, generates a secure WUR signal by replacing the address field of the WUR frame with the MIC; and a transmitter which, in operation, transmits the secure WUR signal.