Network authentication method for secure electronic transactions

A network authentication method to foe 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 comprising the steps of:

• a) storing, by the verification server, a certificate that is assigned to the end user, and a public key that corresponds uniquely to the certificate, the certificate including a unique user identifier (UID) of the end user;
• b) storing, by the client device, a certificate reference that is mapped uniquely to the certificate assigned to the end user, and a reference first private key portion that is obtained by encrypting a first private key portion of a private key with a personal identification number (PIN) code that is determined by the end user, the public key and the private key cooperatively constituting an asymmetric key pair corresponding to the end user, the private key being capable of being divided into the first private key portion and a second private key portion;
• c) by the client device, after receipt of the second private key portion and 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 first private key portion stored in step b) with the user input code to obtain a current key portion, combining the current key portion and the second private key portion received thereby into 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 corresponding to 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.