A network authentication method to be implemented using a client device and a verification server that are connected to a communication network, the client device being associated with an end user and storing an authentication application, said network authentication method being characterized by the steps of: a) storing, by the verification server, a certificate that is assigned to the end user, the certificate including a unique user identifier of the end user, and an asymmetric key pair of a public key and a private key;; b) storing, by the client device, a certificate reference that is mapped uniquely to the certificate assigned to the end user, and a reference private key that is obtained by encrypting the private key with a personal identification number code that is determined by the end user; c) by the client device, after receipt of transaction data that is associated with an electronic transaction between the client device and a network server and that is to be confirmed by the end user, in response to execution of the authentication application, generating a user input code through an input operation, decrypting the reference private key stored in step b) with the user input code to obtain a current key, and generating a digital signature for the transaction data using the current key and the transaction data; and d) by the verification server, upon receipt of a digital signature and a certificate reference via the communication network, determining, based on the public key of the certificate to which the certificate reference received thereby is uniquely mapped, whether or not the digital signature received thereby is signed with the private key, and obtaining from the digital signature received thereby the transaction data that has been determined to be associated with the end user and that has been confirmed by the end user when it is determined that the digital signature is signed with the private key. a) storing, by the verification server, a certificate that is assigned to the end user, the certificate including a unique user identifier of the end user, and an asymmetric key pair of a public key and a private key;; b) storing, by the client device, a certificate reference that is mapped uniquely to the certificate assigned to the end user, and a reference private key that is obtained by encrypting the private key with a personal identification number code that is determined by the end user; c) by the client device, after receipt of transaction data that is associated with an electronic transaction between the client device and a network server and that is to be confirmed by the end user, in response to execution of the authentication application, generating a user input code through an input operation, decrypting the reference private key stored in step b) with the user input code to obtain a current key, and generating a digital signature for the transaction data using the current key and the transaction data; and d) by the verification server, upon receipt of a digital signature and a certificate reference via the communication network, determining, based on the public key of the certificate to which the certificate reference received thereby is uniquely mapped, whether or not the digital signature received thereby is signed with the private key, and obtaining from the digital signature received thereby the transaction data that has been determined to be associated with the end user and that has been confirmed by the end user when it is determined that the digital signature is signed with the private key.