Abstract: Embodiments described herein provide various designs of multi-frequency radio frequency identification (RFID) tags which are compact in size and tamper-proofing. In one aspect, a proposed multi-frequency RFID tag includes both a high frequency (HF) subsystem and an ultra-high frequency (UHF) subsystem. The HF subsystem and the UHF subsystem share a common integrated circuit (IC) chip and a common substrate. The HF subsystem further includes a HF loop antenna coupled to the IC chip. The UHF subsystem further includes a coupling antenna electrically coupled to the IC chip but electrically isolated from the HF loop antenna. The UHF subsystem also includes an UHF antenna having a region for receiving the RFID module. When the RFID module is positioned within the receiving region of the UHF antenna, the UHF antenna is coupled to the IC chip in the RFID module via the coupling antenna, thereby forming the UHF subsystem.

Abstract: A system for providing item information includes: a radio frequency identification (RFID) tag coupled to an item; and a mobile device comprising an RFID reader. The RFID tag includes stored information related to the item, and the RFID reader is configured to access the RFID tag, obtain the item information, and communicate the item information to a user.

Abstract: A method for collision avoidance in a multi-reader environment comprising a plurality of Radio Frequency Identification (RFID) interrogators, the method comprises each of the plurality of interrogators entering a quiet state during which none of the interrogators transmits, each of the plurality of interrogators selecting a transmit time after the quiet period during which each of the interrogator will attempt to transmit, each of the plurality of interrogators monitoring their associated receive path, an interrogator of the plurality of interrogators transmitting an instruction during its selected transmit time indicating the beginning of a session when the interrogator does not detect data on its receive path prior to its select transmit time, the interrogator comparing its receive path to its transmit path when it transmits the instruction, the interrogator returning to the quiet state when the receive path does not match the transmit path, and the interrogator completing the session when the receive path

Abstract: A method for mutual authentication in an RFID system comprising an RFID reader and an RFID tag, the method comprising requesting an identification from the tag, receiving the identification, using the received identification to select a password associated with the identification, generating a password key based on the selected password, encrypting the selected password using the password key, and transmitting the encrypted password to the tag.

Abstract: Embodiments described herein provide various designs of multi-frequency radio frequency identification (RFID) tags which are compact in size and tamper-proofing. In one aspect, a proposed multi-frequency RFID tag includes both a high frequency (HF) subsystem and an ultra high frequency (UHF) subsystem. The HF subsystem and the UHF subsystem share a common integrated circuit (IC) chip and a common substrate. The HF subsystem further includes a HF loop antenna coupled to the IC chip. The UHF subsystem further includes a coupling antenna electrically coupled to the IC chip but electrically isolated from the HF loop antenna. The UHF subsystem also includes an UHF antenna having a region for receiving the RFID module. When the RFID module is positioned within the receiving region of the UHF antenna, the UHF antenna is coupled to the IC chip in the RFID module via the coupling antenna, thereby forming the UHF subsystem.

Abstract: A method for authenticating a document comprises obtaining the contents of a document, obtaining biometric characteristics from an individual, forming a message based on the contents of the document and the biometric characteristics of the individual, generating a digital signature based on the message and a key, and writing the digital signature to an Radio Frequency Identification (RFID) tag affixed to the document.

Abstract: A radio frequency identification (RFID) switch tag is disclosed. This RFID switch tag includes a base component having an ultra-high frequency (UHF) booster, and a detachable component having at least one UHF RFID module and a high frequency (HF) RFID module. In some embodiments, the detachable component is positioned in close proximity to the base component in a first configuration of the RFID switch tag such that the at least one UHF RFID module is sufficiently coupled to the UHF booster in the base component to form an UHF RFID system having a desired performance. The detachable component can also be separated from the base component to obtain a second configuration of the RFID switch tag, and the HF RFID module remains functional within the detached detachable component so that the detachable component can be used as a standalone HF RFID tag.

Abstract: RFID tags are used for many purpose including tracking. RFID interrogators are used to retrieve information from tags. In many applications, a plurality of RFID interrogators are required. Synchronization between interrogators in the same theater of operation is critical to ensure that their broadcasts do not interfere with each other. In fixed RFID interrogator applications, RFID interrogators can be wired together allowing a channel to synchronize the transmissions of the RFID interrogators. Methods described herein can ensure that synchronization is maintained in the event of the failure of a synchronizing master. Furthermore, additional methods for synchronizing RFID interrogators in wireless applications are described allowing synchronization in the absence of wired connections between interrogators.

Abstract: A method for updating a group encryption key association, the method includes receiving an encrypted group key from a second device, where the group key has been encrypted using a device key of a first device. The method further includes, in the first device, using the group key to encrypt an input vector, transmitting the encrypted input vector, encrypting privacy-sensitive information using a device key, an encryption algorithm, and the input vector, and transmitting the encrypted privacy-sensitive information to the second device.

Abstract: A radio frequency identification (RFID) transponder that includes an RFID chip, a loop that is electrically connected to the RFID chip, and a substantially transparent antenna coupled to the loop. In various embodiments, the RFID transponder can be affixed over a light source (e.g., vehicle headlights) while preserving the luminance from the light source. Alternately or in addition, the RFID transponder can be affixed to a surface (e.g., product packaging, license plates) without obscuring any marks, designs, motifs, and/or text on the surface.