Method, authentication medium and device for securing access to a piece of equipment

A device for securing access to a piece of equipment, comprising:

• an authentication medium which is supplied with a reference datum;
• a sensor obtaining, during every access request formulated by a party requesting access to the equipment, a biometric signature of said party requesting access;
• and a controller included in the authentication medium and selectively authorising the party requesting access to access the piece of equipment in accordance with the result of a verification of the authenticity of the biometric signature of the party requesting access by means of the reference datum wherein the controller comprises a decryption module and a comparison module wherein the reference datum supplied to the authentication medium comprises an encrypted version of an authentic biometric signature allegedly attributed to the party requesting access, wherein the decryption module uses a secret key by means of which it secretly reconstructs, upon each access request, the authentic biometric signature from its encrypted version and wherein the comparison module secretly compares the biometric signature obtained from the party requesting access with the reconstructed authentic biometric signature and supplies a comparison result that constitutes the result of the verification.