Abstract: A method for authentication of a user (1) to an acceptance point (3), the authentication being performed by comparing a transaction number (Trx1D) with a computed or stored transaction number (Trx1D), wherein the acceptance point (3) and/or a user terminal (2) sends a request message to a central point (4) and the central point (4) provides and transmits a temporarily valid transaction number (Trx1D) by means of which authentication of the user (1) to the acceptance point (3) can be performed, or that the acceptance point (3) provides a temporarily valid transaction number (Trx1D) by means of which authentication of the user (1) to a central point (4) can be performed, an authorization after successful authentication to the central point (4) being performed by the generation and transmission of an authorization message from the central point (4) to the acceptance point (3).