It is presented a security server arranged to set up communication between a merchant device and a customer payment application. The security server comprises: a receiver arranged to receive a first message comprising a customer identifier, an application identifier and a security token; a determiner arranged to determine whether the merchant device is authorized; a transmitter arranged to send a second message to the merchant device, the second message indicating that the merchant device is authorized to effect payment; and a channel establisher arranged to set up a secure channel between the merchant device and the customer payment application in a secure element being adapted to be comprised in a mobile communication terminal, wherein all communication between the merchant device and the customer payment application is controlled by the security server. Corresponding methods, merchant device, computer programs and computer program products are also presented.