Item identification via RFID tag secret

    公开(公告)号:US12086668B1

    公开(公告)日:2024-09-10

    申请号:US18316311

    申请日:2023-05-12

    申请人: Impinj, Inc.

    摘要: 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.

    RFID ICs with privacy modes
    2.
    发明授权

    公开(公告)号:US12039390B2

    公开(公告)日:2024-07-16

    申请号:US17762940

    申请日:2020-10-28

    申请人: Impinj, Inc.

    摘要: RFID tag ICs may be configured with privacy modes. When a tag IC is in a privacy mode, it will not respond to commands unless a previous command includes correct verification information or specifies a recycling indicator of the tag IC. If the previous command includes correct verification information, then the tag IC will respond to one or more subsequent commands as normal, for example by responding with one or more identifiers. If the previous command does not include correct verification information but specifies a recycling indicator and the privacy mode is recycling-enabled, the tag IC may respond to one or more subsequent commands with recycling information. The recycling information identifies whether or how an item associated with the RFID IC can be recycled or disposed but does not otherwise identify the RFID IC or item. Otherwise, the tag IC may remain silent.

    Environment-based RFID IC behavior

    公开(公告)号:US11798392B1

    公开(公告)日:2023-10-24

    申请号:US17749292

    申请日:2022-05-20

    申请人: Impinj, Inc.

    摘要: 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.

    RFID tags enforcing persistence while powered

    公开(公告)号:US11783140B1

    公开(公告)日:2023-10-10

    申请号:US17547416

    申请日:2021-12-10

    申请人: Impinj, Inc.

    IPC分类号: G06K7/10

    CPC分类号: G06K7/10217 G06K7/10138

    摘要: RFID tags may compensate for non-RFID power sources by automatically enforcing data or state persistence even while powered. A tag may measure a time interval between successive detected modulated reader transmissions. If the interval exceeds a minimum time, then the tag may deassert a protocol flag, erase data, and/or change tag operating states, even if the tag would normally not perform these actions while powered.

    RFID loss-prevention based on transition risk

    公开(公告)号:US11748703B1

    公开(公告)日:2023-09-05

    申请号:US17592598

    申请日:2022-02-04

    申请人: Impinj, Inc.

    摘要: An RFID loss-prevention system (LPS) may monitor RFID-tagged items in a facility. An RFID reader transmits a first inventory command configured to cause tags in a first state to respond, receive a reply from a first tag, determine that the first tag has a low transition risk, and cause the first tag to switch to a second state. The reader may also receive a reply from a second tag, determine that the second tag has a high transition risk, and cause the second tag to remain in the first state. The reader may then transmit a second inventory command configured to cause tags in the first state to respond, receive a reply from the second tag in response to the second inventory command, determine that the second tag has inappropriately exited the facility, and issue an alert.

    Enhanced RFID tag authentication
    7.
    发明授权

    公开(公告)号:US11361174B1

    公开(公告)日:2022-06-14

    申请号:US16871101

    申请日:2020-05-11

    申请人: Impinj, Inc.

    IPC分类号: G06K7/10 H04L9/32

    摘要: An authentication method includes RFID tags authenticating RFID readers. A tag sends a tag identifier and a reader challenge to a reader in response to one or more commands from the reader. The reader then either derives a response to the reader challenge itself or has a verification authority derive the response. The response may be derived from parameter(s) in the reader challenge, and may be derived using a cryptographic key. The reader then sends the response to the tag along with one or more commands. The tag verifies the response before executing action(s) associated with the command(s).

    High-speed RFID tag assembly using impulse heating

    公开(公告)号:US11288564B1

    公开(公告)日:2022-03-29

    申请号:US17101085

    申请日:2020-11-23

    申请人: Impinj, Inc.

    摘要: RFID inlays or straps may be assembled using impulse heating of metal precursors. Metal precursors are applied to and/or included in contacts on an RFID IC and/or terminals on a substrate. During assembly of the tag, the IC is disposed onto the substrate such that the IC contacts physically contact either the substrate terminals or metal precursors that in turn physically contact the substrate terminals. Impulse heating is then used to rapidly apply heat to the metal precursors, processing them into metallic structures that electrically couple the IC contacts to the substrate terminals.

    Location-based access to RFID tag information

    公开(公告)号:US10733395B1

    公开(公告)日:2020-08-04

    申请号:US16270611

    申请日:2019-02-08

    申请人: Impinj, Inc.

    摘要: Embodiments are directed to restricting access to Radio Frequency Identification (RFID) tag information based on location. Access to RFID tag information may be restricted at the reader level, at the requester level, and at the network level. When reader-level restrictions exist, devices may be prevented from inventorying tags and retrieving information from tags. When requester-level restrictions exist, a requester or device may be prevented from receiving tag information from inventoried tags or a network. When network-level restrictions exist, a network may discard or otherwise restrict tag information received from devices.

    RFID loss-prevention based on transition risk

    公开(公告)号:US10521768B1

    公开(公告)日:2019-12-31

    申请号:US16455792

    申请日:2019-06-28

    申请人: Impinj, Inc.

    摘要: An RFID loss-prevention system (LPS) may monitor RFID-tagged items in a facility. An RFID reader transmits a first inventory command configured to cause tags in a first state to respond, receive a reply from a first tag, determine that the first tag has a low transition risk, and cause the first tag to switch to a second state. The reader may also receive a reply from a second tag, determine that the second tag has a high transition risk, and cause the second tag to remain in the first state. The reader may then transmit a second inventory command configured to cause tags in the first state to respond, receive a reply from the second tag in response to the second inventory command, determine that the second tag has inappropriately exited the facility, and issue an alert.