The aim of this invention is to assure the portability of an electronic certificate and the security of the private key which are part of the certificate X509. In fact, it is important that this certificate is not used for purposes uncontrolled by the holder, such as identity usurpation, the authorization of non-desired transactions or the reproduction of transactions (replay). This aim is reached by a storage and transporting method for an electronic certificate, said certificate having an authority section for the issuing authority, a holder section for the holder of the certificate and a signature section determined by the issuing authority, characterized in that all or part of the holder section is contained in a removable security module and that at least the authority section is contained in a host computer.