A network authentication method to be implemented by a network authentication system for secure verification of the identity of a user, the network authentication system including a user terminal operated by the user, a content-provider server, a verification server, and a portable personal electronic device carried by the user, the user terminal, the content-provider server and the verification server being connected to a communication network, the portable personal electronic device being capable of connection with the communication network and/or short-distance wireless communication with the user terminal, said network authentication method being characterized by the steps of: a) upon receipt of correct user login data, which includes a user identifier, from the user terminal via the communication network, the content-provider server transmitting a verification request, which includes the user identifier, to the verification server via the communication network; b) after receipt of the verification request from the content-provider server, the verification server further receiving hardware identification data and positioning information that are associated with the user terminal and the portable personal electronic device via the communication network; c) in response to the verification request, the verification server determining whether the hardware identification data obtained in step b) matches or is a subset of reference hardware identification data, which is pre-stored in the verification server and which corresponds to the user identifier, and judging, based on the positioning information, whether the user terminal and the portable personal electronic device are in close proximity to each other; and d) upon detecting that a match exists or that the hardware identification data is a subset of the reference hardware identification data and judging that the user terminal and the portable personal electronic device are in close proximity to each other, the verification server transmitting a verification reply indicating successful authentication of the identity of the user to the content-provider server via the communication network. a) upon receipt of correct user login data, which includes a user identifier, from the user terminal via the communication network, the content-provider server transmitting a verification request, which includes the user identifier, to the verification server via the communication network; b) after receipt of the verification request from the content-provider server, the verification server further receiving hardware identification data and positioning information that are associated with the user terminal and the portable personal electronic device via the communication network; c) in response to the verification request, the verification server determining whether the hardware identification data obtained in step b) matches or is a subset of reference hardware identification data, which is pre-stored in the verification server and which corresponds to the user identifier, and judging, based on the positioning information, whether the user terminal and the portable personal electronic device are in close proximity to each other; and d) upon detecting that a match exists or that the hardware identification data is a subset of the reference hardware identification data and judging that the user terminal and the portable personal electronic device are in close proximity to each other, the verification server transmitting a verification reply indicating successful authentication of the identity of the user to the content-provider server via the communication network.