Contactless privacy protection device
AssigneeCommissariat a l'Energie Atomique
InventorsOlivier Savry, Francois Vacherand, Elisabeth Crochon
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Abstract
A privacy protection method designed to prevent or authorize a communication between a reader and an RFID label situated in an efficiency zone. In the method a) there is permanent detection of possible variation of an ambient magnetic field in one or more frequency bands allocated to the RFID labels, and b) in the event of detection of an instantaneous variation of the local magnetic field and in the absence of inhibition, a parameter value of a magnetic circuit is modified so that the instantaneous value of the local magnetic field is modified.
Claims11
A privacy protection method to prevent or authorize a communication between a reader and at least one RFID label situated in an efficiency zone, implemented by a privacy protection device separate from the reader and the RFID label, comprising:
- a) detecting a possible variation of a local magnetic field in one or more frequency bands allocated to the RFID label, corresponding to a request emitted by the reader to the RFID label or to a response from the RFID label to the reader;
- and
- b) in an event of detection of the possible variation, scrambling the request emitted by the reader or the response from the RFID label by modifying a parameter value of a magnetic circuit of the privacy protection device so as to counter modulate a load to modify the request emitted by the reader,
- wherein the modifying the parameter of a magnetic circuit provided in b) includes producing a signal that is representative of a difference between a signal representative of a mean value and a signal representative of an instantaneous value of the local magnetic field and using the difference to modify the parameter so as to bring the instantaneous value of the local magnetic field to its mean value.
A privacy protection device to prevent or authorize a communication between a reader and at least one RFID label in an efficiency zone of the device, comprising:
- means for detecting a variation of a local magnetic field in one or more RFID frequency bands, corresponding to a request emitted from the reader to the RFID label or a response from the RFID label to the reader, and producing a detection signal when a variation of the magnetic field is detected;
- means for forming an antenna;
- a load variable by a command coupled to the means for forming the antenna;
- and
- command means for commanding a variation of the load after reception of the detection signal to scramble the request emitted by the reader or the response from the RFID label respectively by modifying the request emitted by the reader,
- wherein the command means modifies the request by producing a signal that is representative of a difference between a signal representative of a mean value and a signal representative of an instantaneous value of the local magnetic field and using the difference to modify the request so as to bring the instantaneous value of the local magnetic field to its mean value.
Dependencies are inferred from the claim text.