Patent ID: 9485092
Filing Date: 2016-11-01
CPC Classification: G06Q,H04L

Claim Text:
1. A transaction device for establishing a shared secret with a point of interaction (POI) over a communications network to enable encrypted communications between the transaction device and the point of interaction, the device comprising: an input arranged to receive communications from the point of interaction; a processor arranged to generate a first communication according to a Diffie-Hellman protocol; an output arranged to send the first communication to the point of interaction; wherein the processor is arranged to apply a randomly generated blinding factor, r, and a static public key, Qc, when generating the first communication, the static public key being unknown to the point of interaction prior to the first communication being generated; and wherein, in response to receiving a second communication from the point of interaction at the input, the second communication having been generated according to the Diffie-Hellman protocol, the processor is arranged to apply the randomly generated blinding factor and generate a shared secret according to the Diffie-Hellman protocol in dependence on data contained within the second communication.