Abstract: RFID ICs sense and indicate changes in their surrounding environment, such as changes in temperature, humidity, chemical presence, RF signals, and similar. An RFID IC indicates when a significant environmental change has occurred, for example by adjusting the value of a flag, writing data to memory, transmitting a message to an external entity, exiting a sleep state, and/or responding repeatedly to an inventorying reader. In some cases, RFID IC actively notifies an external entity that a significant environmental change has been sensed. For example, RFID IC may alert the external entity by participating in a special inventory process meant for RFID ICs sending environmental change. The RFID IC may alert the external entity by interjecting itself into an inventory round, re-participating in an inventory round, refraining from entering a sleep state after inventorying, and/or adjusting timing of a scheduled reply to communicate with an RFID reader ahead of schedule.

Abstract: A method is provided to determine unique identifiers. A physical item has an RFID integrated circuit (IC) having a unique identifier and a secret. The RFID IC may be configured to provide an identifier portion and a response to a previously sent challenge, where the identifier portion by itself is insufficient to completely identify the IC or item and the response is based on the challenge and the secret. Attempts are made to verify the response using a set of potential secrets determined using the identifier portion. If the response is successfully verified using a certain secret, the secret may then be used to determine one or more other identifier portions. The unique, complete identifier may then be determined from a combination of at least the identifier portions.

Abstract: RFID ICs sense and indicate changes in their surrounding environment, such as changes in temperature, humidity, chemical presence, RF signals, and similar. An RFID IC indicates when a significant environmental change has occurred, for example by adjusting the value of a flag, writing data to memory, transmitting a message to an external entity, exiting a sleep state, and/or responding repeatedly to an inventorying reader. In some cases, RFID IC actively notifies an external entity that a significant environmental change has been sensed. For example, RFID IC may alert the external entity by participating in a special inventory process meant for RFID ICs sending environmental change. The RFID IC may alert the external entity by interjecting itself into an inventory round, re-participating in an inventory round, refraining from entering a sleep state after inventorying, and/or adjusting timing of a scheduled reply to communicate with an RFID reader ahead of schedule.

Abstract: RFID technology may be used to provide digital identities for physical items. An RFID IC attached to or integrated into a physical item contains an identifier for the physical item. Digital identity information associated with the item, such as ownership information, history, properties, and the like, may be located on one or more networks. An entity, after authenticating itself and/or the item, may use the identifier to locate, retrieve, and/or update the item's digital identity information on the network.

Abstract: A method is provided to determine unique identifiers. A physical item has an RFID integrated circuit (IC) having a unique identifier and a secret. The RFID IC may be configured to provide an identifier portion and a response to a previously sent challenge, where the identifier portion by itself is insufficient to completely identify the IC or item and the response is based on the challenge and the secret. Attempts are made to verify the response using a set of potential secrets determined using the identifier portion. If the response is successfully verified using a certain secret, the secret may then be used to determine one or more other identifier portions. The unique, complete identifier may then be determined from a combination of at least the identifier portions.

Abstract: A Radio Frequency Identification (RFID) integrated circuit (IC) is at least partially covered by a repassivation layer that is, in turn, at least partially covered by a large, electrically conductive contact pad. The repassivation layer is disposed so as to leave uncovered at least one IC contact. The large contact pad is disposed so as to cover the IC IC contact. The large contact pad forms a first galvanic coupling to the IC contact and a second galvanic coupling to a tag antenna. The surface area of the first galvanic coupling is substantially smaller than the surface area of the second galvanic coupling.

Abstract: RFID ICs sense and indicate changes in their surrounding environment, such as changes in temperature, humidity, chemical presence, RF signals, and similar. An RFID IC indicates when a significant environmental change has occurred, for example by adjusting the value of a flag, writing data to memory, transmitting a message to an external entity, exiting a sleep state, and/or responding repeatedly to an inventorying reader. In some cases, RFID IC actively notifies an external entity that a significant environmental change has been sensed. For example, RFID IC may alert the external entity by participating in a special inventory process meant for RFID ICs sending environmental change. The RFID IC may alert the external entity by interjecting itself into an inventory round, re-participating in an inventory round, refraining from entering a sleep state after inventorying, and/or adjusting timing of a scheduled reply to communicate with an RFID reader ahead of schedule.

Abstract: RFID technology may be used to provide digital identities for physical items. An RFID IC attached to or integrated into a physical item contains an identifier for the physical item. Digital identity information associated with the item, such as ownership information, history, properties, and the like, may be located on one or more networks. An entity, after authenticating itself and/or the item, may use the identifier to locate, retrieve, and/or update the item's digital identity information on the network.

Abstract: A method is provided to determine unique identifiers. A physical item has an RFID integrated circuit (IC) having a unique identifier and a secret. The RFID IC may be configured to provide an identifier portion and a response to a previously sent challenge, where the identifier portion by itself is insufficient to completely identify the IC or item and the response is based on the challenge and the secret. Attempts are made to verify the response using a set of potential secrets determined using the identifier portion. If the response is successfully verified using a certain secret, the secret may then be used to determine one or more other identifier portions. The unique, complete identifier may then be determined from a combination of at least the identifier portions.

Abstract: Methods and systems are described for authorizing an item with an RFID tag to leave a facility. In one embodiment, a mobile device receives or determines an exit code (EC) to write into the tag in response to providing authorizing information. The EC may be based on information stored in the tag such as the tag's item identifier or other tag information (collectively an item identifier or II), a ticket value, other information such as the OC, a mobile identity or location, or any other suitable information. Upon verification of the EC, the tagged item is allowed to leave the facility. In another embodiment, the mobile device stores an item identifier (II) associated with the tag and provides authorizing information. Upon verifying the authorizing information and confirming that the stored II corresponds to the tagged item's II, the tagged item is allowed to leave the facility.

Abstract: RFID ICs sense and indicate changes in their surrounding environment, such as changes in temperature, humidity, chemical presence, RF signals, and similar. An RFID IC indicates when a significant environmental change has occurred, for example by adjusting the value of a flag, writing data to memory, transmitting a message to an external entity, exiting a sleep state, and/or responding repeatedly to an inventorying reader. In some cases, RFID IC actively notifies an external entity that a significant environmental change has been sensed. For example, RFID IC may alert the external entity by participating in a special inventory process meant for RFID ICs sending environmental change. The RFID IC may alert the external entity by interjecting itself into an inventory round, re-participating in an inventory round, refraining from entering a sleep state after inventorying, and/or adjusting timing of a scheduled reply to communicate with an RFID reader ahead of schedule.

Abstract: Messages may be passed between Radio Frequency Identification (RFID) tags using RFID readers. A first tag with a message intended for a second tag sends the message to an RFID reader. The reader then determines that the destination of the message is the second tag and sends the message to the second tag. The second tag may confirm receipt of the message by sending a receipt confirmation message to the reader for forwarding to the first tag, and/or the reader may itself confirm that the message was sent to the second tag by sending a transmit confirmation message to the first tag.

Abstract: RFID technology may be used to provide digital identities for physical items. An RFID IC attached to or integrated into a physical item contains an identifier for the physical item. Digital identity information associated with the item, such as ownership information, history, properties, and the like, may be located on one or more networks. An entity, after authenticating itself and/or the item, may use the identifier to locate, retrieve, and/or update the item's digital identity information on the network.

Abstract: Methods and systems are described for authorizing an item with an RFID tag to leave a facility. In one embodiment, a mobile device receives or determines an exit code (EC) to write into the tag in response to providing authorizing information. The EC may be based on information stored in the tag such as the tag's item identifier or other tag information (collectively an item identifier or II), a ticket value, other information such as the OC, a mobile identity or location, or any other suitable information. Upon verification of the EC, the tagged item is allowed to leave the facility. In another embodiment, the mobile device stores an item identifier (II) associated with the tag and provides authorizing information. Upon verifying the authorizing information and confirming that the stored II corresponds to the tagged item's II, the tagged item is allowed to leave the facility.

Abstract: A Radio Frequency Identification (RFID) integrated circuit (IC) is at least partially covered by a repassivation layer that is, in turn, at least partially covered by a large, electrically conductive contact pad. The repassivation layer is disposed so as to leave uncovered at least one IC contact. The large contact pad is disposed so as to cover the IC IC contact. The large contact pad forms a first galvanic coupling to the IC contact and a second galvanic coupling to a tag antenna. The surface area of the first galvanic coupling is substantially smaller than the surface area of the second galvanic coupling.

Abstract: Methods and systems are described for authorizing an item with an RFID tag to leave a facility. In one embodiment, a mobile device receives or determines an exit code (EC) to write into the tag in response to providing authorizing information. The EC may be based on information stored in the tag such as the tag's item identifier or other tag information (collectively an item identifier or II), a ticket value, other information such as the OC, a mobile identity or location, or any other suitable information. Upon verification of the EC, the tagged item is allowed to leave the facility. In another embodiment, the mobile device stores an item identifier (II) associated with the tag and provides authorizing information. Upon verifying the authorizing information and confirming that the stored II corresponds to the tagged item's II, the tagged item is allowed to leave the facility.

Abstract: Messages may be passed between Radio Frequency Identification (RFID) tags using RFID readers. A first tag with a message intended for a second tag sends the message to an RFID reader. The reader then determines that the destination of the message is the second tag and sends the message to the second tag. The second tag may confirm receipt of the message by sending a receipt confirmation message to the reader for forwarding to the first tag, and/or the reader may itself confirm that the message was sent to the second tag by sending a transmit confirmation message to the first tag.

Abstract: An RFID tag may execute instructions from an authenticated RFID reader. A tag determines a handle and a first parameter, both of which may be random numbers, and sends the handle to a reader. Upon receiving a challenge from the reader, the tag determines and sends a cryptographic response to the challenge based on an algorithm, a tag key, the first parameter, and the challenge. Upon receiving a message with a second parameter and a tag instruction, the tag executes the tag instruction upon verifying that the second parameter derives from the first parameter and the tag handle.

Abstract: An RFID tag may execute instructions from an authenticated RFID reader. A tag determines a handle and a first parameter, both of which may be random numbers, and sends the handle to a reader. Upon receiving a challenge from the reader, the tag determines and sends a cryptographic response to the challenge based on an algorithm, a tag key, the first parameter, and the challenge. Upon receiving a message with a second parameter and a tag instruction, the tag executes the tag instruction upon verifying that the second parameter derives from the first parameter and the tag handle.

Abstract: An RFID tag possesses a group key issued by an authorized entity. When a reader requests some information from the tag, such as an identifier, the tag transmits a random number to the reader. The tag then determines one or more reader characteristics based on a response received from the reader. In one embodiment, the tag generates a verification value based on the random number and the group key and compares the verification value to the received response. If the comparison succeeds, the tag may treat the reader as possessing particular functionality, authorized to implement a particular feature, and/or authorized to receive information from the tag. If the comparison fails, the tag may treat the reader as lacking particular functionality, not authorized to implement a particular feature, and/or not authorized to receive information from the tag. The tag may request additional response(s) from the reader before determining the reader characteristic(s).