Patent ID: 8022810
Filing Date: 2011-09-20
Classification: G06K,H04B

Abstract:
1. 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.