Abstract: The present invention provides a method and system for creating non-repudiated digital receipts and electronic signatures for electronic transactions. More specifically, the present invention provides a method, computer program and system for authorizing an electronic data transfer. An authentication request containing a digital certificate is received from a requesting device via a communication link. The present invention then determines whether the digital certificate is valid, and creates an authentication response denying the authentication request when the digital certificate is not valid, or approving the authentication request when the digital certificate is valid. The authentication response is then sent to the requesting device via the communication link, and information about the electronic data transfer, the digital certificate and at least a portion of the authentication response are stored.