An apparatus for using a certificate on a device is proposed, including a processing unit for generating a certificate request and a transmitter-receiver unit for transmitting the generated certificate request to a first external computing unit, which is configured to generate a certificate for the device and to allow a second external computing unit to re-sign the certificate with an additional manufacturer's signature, and for receiving the re-signed certificate from the external computing unit. The processing unit is further configured to check the manufacturer's signature based on information stored in the device and to use the certificate depending on a result of the check. Furthermore, a system and a corresponding method are proposed.