US Patent 11395136 Impairment based physical layer fingerprint

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless device may receive a beamformed signal from a transmitting device. The wireless device may estimate a weighted sum based at least in part on one or more coefficients that relate to impairments associated with the transmitting device, a spatial location of the wireless device, and/or the like. The wireless device may determine a cryptographic key based at least in part on a ratio among the plurality of coefficients in the weighted sum, and one or more communications between the wireless device and the transmitting device may be secured based on the cryptographic key. Numerous other aspects are provided.