Abstract: The present invention relates to a method for a receiving device operated by a buyer of performing payment of content to be received from a transmitting device operated by a seller, said method comprises the steps of: setting up a private communication channel between said receiving device and said transmitting device, transmitting a payment container to said transmitting device using said private communication channel, said payment container comprising information authorizing the seller to receive the payment from the buyers bank, receiving said content from said transmitting device based on the arrival of said payment container at said transmitting device. Thereby secure and convenient payment from consumer to consumer or consumer to business is provided, even if no permanent far-range connection to a trust centre or transaction manager is available.

Abstract: The present invention relates to a method of ensuring integrity when transmitting data from a transmitting device to a receiving device, wherein said method comprises the step of adding a token to said data before transmitting said data. Thereby, by comparing transmitter tokens, the receiver can cancel out unwanted multiple copies of the same message originating from the same transmitting device. This can be performed without the sender knowing the real identity of the user operating the transmitting device. The token could e.g. be a random number, and if the chosen random number interval is large, the probability for other transmitting devices to create the same number is minimized.