Patent ID: 8550360

Claim:
A contactless portable object comprising a main radiofrequency device made up of a main chip and a main antenna connected together so that when the portable object enters an electromagnetic field of a suitable reader, the main radiofrequency device provides power to the chip and ensures communication between the chip and the reader, wherein said contactless portable object further comprising a secondary contactless device comprising a secondary antenna and an electric circuit, with the main radiofrequency device and the secondary radiofrequency device both supported on a flat surface of the portable object, with the main radiofrequency device placed so as to encircle the secondary device, and with the electric circuit of the secondary contactless device set up in such a way that, when the two antennas enter said electromagnetic field of a suitable reader at the same time, and an amount of energy required to power said electric circuit and have it operational is less than an amount of energy required to power the main chip and have it operational, said electric circuit is powered and makes reading of data of the main chip impossible, wherein said electric circuit is configured to transmit random data as soon as it receives the amount of energy required for its operation, so that the transmission of random data occurs before the main chip can exchange data with the reader.