Abstract: There is provided a method for authenticating the proximity of at least two devices, the method comprising: generating at least one packet; emitting at least one acoustic wave from at least one emitting device, each acoustic wave corresponding to a generated packet, at least one acoustic wave being emitted for all the generated packets, all the emitted acoustic waves forming an acoustic wave superposition. The superposition is received with at least one receiving device; assessing the similarity of the received superposition and a comparator; and authenticating proximity of each emitting device and each receiving device when the received superposition and the comparator fulfil a predetermined similarity requirement, wherein the comparator corresponds to a combination of all the generated packets.