Circuit and method for using capacitive touch to further secure information in RFID documents
AssigneeTexas Instruments Incorporated
InventorsPrasanna Parthasarathy, Michael L Mitchell
Life of this patent
Estimating the term…
Abstract
A system for limiting access to confidential information including storage circuitry for storing the confidential information. An access enabling circuit allows access to the storage circuitry in response to a first level of an enabling signal. A processor generates the enabling signal for a predetermined amount of time in response to sensing of a change of a predetermined value that is produced in response to an act by a person responsible for the confidentiality of the confidential information. The enabling signal assumes a second level after the predetermined amount of time to block access to the storage circuitry.
Claims20
A system, comprising:
- a radio frequency identification (RFID) chip, the RFID chip comprising:
- an RFID tag for storing information;
- a power input;
- and
- an enable input;
- and
- a processor coupled to the RFID chip, the processor configured to:
- operate in a first power mode in which the processor is configured to:
- monitor for energy received via an RFID signal;
- in response to the energy received via the RFID signal, transition to a second power mode in which the processor consumes more power than the first power mode;
- and
- operate in the second power mode in which the processor is configured to:
- in response to the transition to the second power mode, measure a capacitance at a capacitive sensor to determine whether a device is in a first physical state or a second physical state;
- assert an enable signal provided to the enable input of the RFID chip in response to the device being in the first physical state;
- and
- inhibit the enable signal in response to the device being in the second physical state.
A method comprising:
- storing, in a radio frequency identification (RFID) tag in an RFID chip, information, the RFID chip comprising an enable input;
- detecting energy received via a radio frequency signal by a processor operating in a first power mode;
- in response to the detecting of the energy, transitioning the processor from the first power mode to a second power mode;
- in response to transitioning the processor from the first power mode to the second power mode, measuring a capacitance at a capacitive sensor;
- determining whether a device is in a first physical state or a second physical state based on the measured capacitance;
- and
- sending, by the processor to the enable input of the RFID chip, an enabling signal such that the RFID chip is enabled based on determining that the device is in the first physical state and the RFID chip is disabled based on determining that the device is in the second physical state.
Dependencies are inferred from the claim text.