For a set (Lk) of embedded systems, an authorized operator with identifier (OP_j) creates a mother public key (KpM) and a mother private key (KsM). The identifier (OP_j), the range of identifiers referenced (Lk) and the mother public key (KpM) are published. For each embedded system (SN_i), a diversified key (KsM_i) is created from the identifier (SN_i) and stored. For every public key (Kp) generated by an embedded system, a cryptographic control value (Sc_i) is calculated on the public key (Kp), an algorithm identifier (CA1) and the utilization parameters (U) of this key, using a zero knowledge signature algorithm, and a certification request message (MRCA) that includes control value (Sc_i), the identifier of the operator (Op_j), and identifier (SN_i) is transmitted to a certification authority, which retrieves the identifier (Op_j) and the value of the mother public key (KpM).