Abstract: An RFID tag is equipped with an energy sensor for receiving an appropriate energy signal or registering an appropriate temperature/environmental level. The RFID tag only responds to a query from an RFID reader if the sensor receives the appropriate stimulation.

Abstract: An RFID tag is equipped with an energy sensor for receiving an appropriate energy signal or registering an appropriate temperature/environmental level. The RFID tag only responds to a query from an RFID reader if the sensor receives the appropriate stimulation.

Abstract: An RFID tag is equipped with an energy sensor for receiving an appropriate energy signal or registering an appropriate temperature/environmental level. The RFID tag only responds to a query from an RFID reader if the sensor receives the appropriate stimulation.

Abstract: A radio frequency identification system comprises a radio-frequency identification substrate and an interrogator. In one embodiment, the radio-frequency identification substrate comprises a plurality of radio-frequency identification devices. In one embodiment, a first radio-frequency identification device on the substrate monitors an indication of a response of a second radio-frequency identification device on the substrate to an interrogation signal and selectively responds to the interrogation signal based on the monitoring of the indication.

Abstract: An RFID tag is equipped with an energy sensor for receiving an appropriate energy signal or registering an appropriate temperature/environmental level. The RFID tag only responds to a query from an RFID reader if the sensor receives the appropriate stimulation.

Abstract: A system and method for limiting the reading out of data from an RFID tag by requiring a reader of the tag to be authenticated by providing the correct key to the tag, static or rotating, before the tag will transmit data. The limitation of transmission is done irrespective of whether the data is encrypted or not. The system and method may have a segmented or tiered access scheme where segments or portions of the data stored in the RFID tag are accessible by differing keys. Additionally, different encryption keys or schemes may be employed to provide differing encryption methods for the data in the differing segments or portions of the data stored in the RFID tag.

Abstract: A mobile key includes an RFID tag associated with a memory. The memory holds a secure access code. An authorization status for a person or item associated with the mobile key is determined by interrogating the mobile key using an RFID interrogation field. Security information, such as a secure identifier or access code, physical measurement data, or biometric data may be provided by the mobile key. The key may also comprise a wireless communication device, such as a cellular telephone. Security information, such as an access code, may be provided to the key using the wireless communication device or other communications network.