Abstract: Server device for performing a transaction in a system having a first entity, such as a POS, a second entity, such as a user having a mobile phone with a digital camera, and a remote server. The first entity generates a code having a transaction information and sends a first message to a server. The second entity, such as a buyer of a product or a user of a service captures the code and transmits a second message to the server having information on the transaction extracted from the code. The transaction is only authorized, when the server has determined that the first message and the second message match with each other. The transaction can be a payment transfer, a grant of an access to a service or a grant of an access to an internet portal.

Abstract: A first entity for communicating with a second entity and a third entity includes a data subdivider for subdividing a data entity into a first data portion and a second data portion. The data portions are processed by an output interface for transmitting a first message to the third entity and the second message to the second entity. In the third entity, the data portion directly received from the first entity and the other data portion received via the second entity are reassembled.