A multimedia network (1) with connected customer stations (2), merchant servers (3), and a payment server (5). Secure electronic transactions are performed using a secure electronic transactions protocol (SET), including exchange of digital certificates, managed by a Trusted Third Party Server (9). The customer stations comprise transactions management means (10), fit for performing said SET protocol and for managing said certificates for the customer station. A remote customer agent (13) represents the customer station in the negotiation and payment process. The customer station (2) comprises an agent interface (12), fit for transmission of codes, parameters and certificates between the customer agent (13) and the transactions management means (10). A remote merchant agent (14) represents the merchant station (3) in the negotiation and payment process with the customer agent (13) or the customer station (3), to have paid for the selected products in a secure way, under control of SET protocol.