Biometric personal authentication

A module (10) for authenticating a person is characterised in that it comprises: - a processing circuit (102) comprising an authentication memory (104), - a sensor (106) of a physiological parameter of the wearer, - a means (108) of deactivating the circuit (102) sensitive to said sensor (106) and capable of deactivating the circuit (102) when said sensor (106) does not receive an expected physiological signal, - a wireless proximity communication circuit (110) with a base, capable of communicating with said base according to a protocol involving biometric data different from said physiological parameter and intended to be received by the module (10), - means (112) of transmitting presence confirmation signals to said base and/or of receiving presence confirmation signals, which are separate from said communication circuit (110).