Method and apparatus for selective blocking of radio frequency identification devices

A method for providing enhanced privacy in an RFID system comprising a plurality of RFID devices, each having an associated identifier, and at least one reader which communicates with one or more of the devices, the method comprising the steps of:

• receiving in a blocker device a communication directed from the reader to one or more of the RFID devices;
• and
• generating in the blocker device an output transmittable to the reader, the output simulating one or more responses from at least one of the RFID devices in a manner which prevents the reader from determining at least a portion of the identifier of at least one of the RFID devices;
• wherein the blocker device comprises a selective blocker tag and the generated output simulates responses of only a subset of all possible identifiers for a given set of RFID devices.

A method for providing enhanced privacy in an RFID system comprising a plurality of RFID devices, each having an associated identifier, and at least one reader which communicates with one or more of the devices, the method comprising the steps of:

• receiving in a blocker device a communication directed from the reader to one or more of the RFID devices;
• and
• generating in the blocker device an output transmittable to the reader, the output simulating one or more responses from at least one of the RFID devices in a manner which prevents the reader from determining at least a portion of the identifier of at least one of the RFID devices;
• wherein the blocker device communicates to the reader information specifying a particular subset of a given set of RFID devices for which the reader will be unable to singulate identifiers.

A method for providing enhanced privacy in an RFID system comprising a plurality of RFID devices, each having an associated identifier, and at least one reader which communicates with one or more of the devices, the method comprising the steps of:

• receiving in a blocker device a communication directed from the reader to one or more of the RFID devices;
• and
• generating in the blocker device an output transmittable to the reader, the output simulating one or more responses from at least one of the RFID devices in a manner which prevents the reader from determining at least a portion of the identifier of at least one of the RFID devices;
• wherein the reader is operative to detect the presence of the blocker device, and to determine if the blocker device is operating as a selective blocker device or a full blocker device.

A method for providing enhanced privacy in an REID system comprising a plurality of RFID devices, each having an associated identifier, and at least one reader which communicates with one or more of the devices, the method comprising the steps of;

• receiving in a blocker device a communication directed from the reader to one or more of the REID devices;
• and
• generating in the blocker device an output transmittable to the reader, the output simulating one or more responses from at least one of the RFID devices in a manner which prevents the reader from determining at least a portion of the identifier of at least one of the RFID devices;
• wherein the reader is operative to detect the presence of the blocker device by interacting with one or more other readers to determine information specifying the physical locations of at least a subset of the RFID devices, and processing the determined location information to ascertain if the blocker device is present.

An RFID system comprising:

• a plurality of RFID devices, each having an associated identifier;
• and
• at least one reader which communicates with one or more of the devices;
• wherein a blocker device is operative to receive a communication directed from the reader to one or more of the RFID devices, and to generate an output transmittable to the reader, the output simulating one or more responses from at least one of the RFID devices in a manner which prevents the reader from determining at least a portion of the identifier of at least one of the RFID devices;
• and
• wherein the blocker device configurable to provide selective blocking of a designated subset of the identifiers for a given set of the RFID devices.