Device fingerprinting is provided for ultra-wide band (UWB) communications. A wireless receiver receives wireless signals including an UWB packet sent from a transmitter. Channel impulse response (CIR) data is extracted from the UWB packet. A device fingerprint of the transmitter is created according to the CIR data, the device fingerprint being representative of physical properties of the wireless signals of the UWB packet. The transmitter is authenticated by the receiver based on the device fingerprint.