Electronic transaction

A communication method for carrying out an electronic transaction, comprising:

• assigning a transaction identifier by a terminal device to the electronic transaction for a time interval starting with transmission of initiation data including the transaction identifier to a mobile device;
• storing the transaction identifier on a terminal host of a computer host system, wherein the terminal host is associated with the terminal device;
• carrying out an initiation communication between the terminal device and the mobile device by means comprising near field communication (NFC), visible light communication, acoustic communication, or a combination thereof, wherein the mobile device is brought into close proximity to the terminal device, wherein the initiation communication between the terminal device and the mobile device is a unidirectional communication in which a data signal comprising the initiation data is transmitted from a communication means of the terminal device to a communication means of the mobile device;
• suppressing, by a transaction application of the mobile device, that the mobile device acts in a transmitting mode for providing transactional data, and, instead effecting that the mobile device acts in a receiving mode for receiving the initiation data from the terminal device;
• upon transmitting the initiation data from the terminal device to the mobile device, carrying out further communications via the internet, respectively between the terminal device and the terminal host and the mobile device and a mobile host of the computer host system, said mobile host being associated with the mobile device, for executing by the computer host system an electronic transaction on the basis of the initiation communication between the terminal device and the mobile device, wherein the further communications comprises transmitting the transaction identifier from the mobile device to the terminal host, in order to initiate carrying out the electronic transaction;
• and
• carrying out the electronic transaction only under the condition that a match between the transmitted transaction identifier and the stored transaction identifier is determined by the terminal host,
• wherein the time interval belongs to a group comprising a predefined time interval and a time interval extending to the end of the electronic transaction, in order to allow the terminal device to securely carry out a plurality of electronic transactions with different mobile devices in parallel based on different transaction identifiers.