A terminal identification method comprising: receiving by a service network, from a terminal, a first request for which signature or certificate verification is to be performed; obtaining by the service network a signature or certificate of a trusted party for a machine identification code identifier of the terminal from the first request, wherein the machine identification code identifier is an identifier allocated by the trusted party to the machine identification code of the terminal, terminals having the same machine identification code identifier being identified as the same terminal; and the service network verifying the obtained signature or certificate, and if the obtained signature or certificate is verified to be legitimate, identifying the terminal using the machine identification code identifier obtained from the signature or certificate; and characterised in that the method further comprises: storing the machine identification code identifier of the terminal and a corresponding machine identification code or a derivative code thereof in a database; the service network receiving, from the terminal, a second request of which machine identification code verification is to be performed; the service network obtaining the machine identification code of the terminal and a signature or certificate from the second request, and after verifying that the signature or certificate is legitimate, querying the corresponding machine identification code or the derivative code in the database based on the machine identification code identifier obtained from the signature or certificate; and if the machine identification code or a derivative code obtained from the second request is different from the machine identification code or the derivative code that are found in the query, declining the request. receiving by a service network, from a terminal, a first request for which signature or certificate verification is to be performed; obtaining by the service network a signature or certificate of a trusted party for a machine identification code identifier of the terminal from the first request, wherein the machine identification code identifier is an identifier allocated by the trusted party to the machine identification code of the terminal, terminals having the same machine identification code identifier being identified as the same terminal; and the service network verifying the obtained signature or certificate, and if the obtained signature or certificate is verified to be legitimate, identifying the terminal using the machine identification code identifier obtained from the signature or certificate; and characterised in that the method further comprises: storing the machine identification code identifier of the terminal and a corresponding machine identification code or a derivative code thereof in a database; the service network receiving, from the terminal, a second request of which machine identification code verification is to be performed; the service network obtaining the machine identification code of the terminal and a signature or certificate from the second request, and after verifying that the signature or certificate is legitimate, querying the corresponding machine identification code or the derivative code in the database based on the machine identification code identifier obtained from the signature or certificate; and if the machine identification code or a derivative code obtained from the second request is different from the machine identification code or the derivative code that are found in the query, declining the request. storing the machine identification code identifier of the terminal and a corresponding machine identification code or a derivative code thereof in a database; the service network receiving, from the terminal, a second request of which machine identification code verification is to be performed; the service network obtaining the machine identification code of the terminal and a signature or certificate from the second request, and after verifying that the signature or certificate is legitimate, querying the corresponding machine identification code or the derivative code in the database based on the machine identification code identifier obtained from the signature or certificate; and if the machine identification code or a derivative code obtained from the second request is different from the machine identification code or the derivative code that are found in the query, declining the request.