Patent Description:
The ISO <NUM>/<NUM>:<NUM> standards specify the radio frequency identification (RFID) signal and data structure for animal identification. The standards lack the specifications for authentication and leave the identification numbers vulnerable to cloning. The existing ISO <NUM>/<NUM> radio frequency identification technologies rely on the manufacturers to guarantee the uniqueness of each animal identification number.

However, with the availability of programmable transponders, the animal identification numbers can easily be cloned by a standard RFID programmer. While existing technologies like NXP's Originality Signature store and retrieve encrypted signatures within the transponder, they use manufacturer specific transponder hardware logic and scanner software. European Patent Application <CIT> discloses a transponder authentication method based on a transponder-specific originality signature. The method involves providing a transponder with a transponder-specific identifier, and providing the transponder with a signature utilized for authentication of the transponder. The signature is generated by signing a part of the transponder-specific identifier, where the signature is stored in a hidden memory of the transponder and generated by signing a part of the transponder-specific identifier with a private key of a private-public key pair. US Patent <CIT> discloses an RFID tag authentication means that performs authentication of a telegram written in the RFID tag. US Patent Application <CIT> discloses a signing method for radio frequency identification application, involving generating signature for tag based on identifier and public key, and storing identifier and signature in tag.

This specification describes means for manufacturers to produce RFID transponders, e.g., ISO <NUM>/<NUM> compliant transponders, with authentication signature using commercially-available transponders and RFID programmers. This specification also describes methods to validate the authentication signature using RFID scanners capable of reading the internal memory of a transponder, thereby authenticating the transponder.

In general, one innovative aspect of the subject matter described in this specification can be embodied in a radio frequency identification (RFID) transponder according to claim <NUM>.

In some implementations, the default telegram includes an identification code and a signature indicator.

In another aspect, the subject matter features a passive integrated transponder (PIT) tag including the transponder.

In yet another aspect, the subject matter features a collar tag including the transponder.

In general, another innovative aspect of the subject matter described in this specification can be embodied in a method according to claim <NUM>.

Implementations of the method can include one or more of the following features and/or features of other aspects. For example, the memory can include a unique identification (UID) code independently established by a third party and the method can further include retrieving the UID code by transmitting the memory-read signal from the scanner to the transponder. The signature can be computationally authenticated based on the default telegram and the UID code. The signature can be generated with the UID code and the default telegram.

The memory-read signal can be transmitted by the scanner after retrieving the default telegram. The scanner can transmit the memory-read signal in response to confirming a signature indicator contained in the default telegram.

The entire signature can be retrieved upon transmitting the memory-read signal from the scanner to the transponder. In certain implementations, a portion of the signature is retrieved with the default telegram.

The method can include validating the transponder upon authentication of the signature.

The transponder can reside within an animal during retrieval of the default telegram and the signature. The method can include identifying the animal after authenticating the signature.

Accordingly, the disclosed method includes several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combinations of elements and arrangement of parts that are adapted to affect such steps, all is exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.

Many systems are designed around the capabilities of RFID transponders, such as licensing and registration of animals, certification of veterinary health certificates, time and attendance systems, and access control, each of which generally implicitly rely of the integrity of the transponder identification code.

The secured transponder technologies disclosed herein advance and promote the objects of identification by frustrating illicit duplication or counterfeiting of transponders placed into service and further strengthens such systems by creating accountability and preventing repudiation of a transponder.

Among other advantages, the secured transponder technologies disclosed herein can advance identification, e.g. animal identification, technologies by enabling signature validation for transponder authentication. In some implementations, the transponders can be used as certificates of authenticity, e.g. in a similar manner to those used for luxury watches, art, memorabilia, etc..

In general, the disclosed technologies relate to a method and system to prevent fraudulent production of a radiofrequency identification (RFID) transponder. For example, the technology can include a signature indicator in the default-read telegram and storing a read-only authentication signature in the internal memory of the transponder. The RFID transponder is compliant with an ISO standard, such as the ISO <NUM>/<NUM> standard. Among other uses, the transponders can be used for animal identification. The transponders can be embedded or attached to a variety of articles, depending on the end use. For example, the transponder can be embedded in a tag, e.g., for attaching to an animal, such as a passive integrated transponder (PIT) tag or a collar tag. In some embodiments, the transponder can be enclosed in a nail or attached to an adhesive substrate.

An example RFID transponder for implementing the method is shown in <FIG>. Here, transponder <NUM> includes a radio frequency transceiver <NUM> and a memory <NUM>. RF transceiver <NUM> generally includes control circuitry (e.g., composed of one or more integrated circuits) and an antenna. Memory <NUM> includes internal memory <NUM> (e.g., read only memory) and field-programmable memory <NUM>. Memory <NUM> is in communication with RF transceiver <NUM>, which receives RF signals <NUM> (e.g., from an RF scanner <NUM>) and transmits RF signals <NUM> (e.g., to RF scanner <NUM>). Generally, the transmitted RF signals <NUM> includes information stored in memory <NUM> that uniquely identifies transponder <NUM>. The information includes a default telegram stored in field-programmable memory <NUM> that is transmitted by transponder <NUM> automatically upon activation by transponder <NUM>. Field-programmable memory <NUM> also includes a signature generated using, at least, a portion of the default telegram (e.g., with just part of the default telegram or with the entire default telegram). Internal memory <NUM> can store information such as a unique identification (ID) code independently established by a third party, such as a manufacturer of the integrated circuit of the memory.

In general, the signature can adopt any public-private key encryption methods, such as AES, ECDSA, and RSA.

Examples of specific protocols for partitioning and retrieving information stored, including the signature, in memory <NUM> are presented below. While the examples use the ISO <NUM>/<NUM> standard, more generally, the innovative concepts disclosed can be applied to other standards too.

<FIG> show a conventional <NUM>-bit ISO FDX telegram <NUM> defined in ISO <NUM>:<NUM> and a conventional <NUM>-bit identification code data content <NUM> defined in <NUM>:<NUM>, <NUM> Amd. <NUM>:<NUM>, and <NUM> Amd. <NUM>:<NUM>, respectively. Identification code <NUM> is part of the data making up telegram <NUM>.

An index used in <FIG>is provided in Table <NUM>.

Turning now to RFID tags that include a signature for authentication, generally the transponder memory is partitioned into two segments: identification data and authentication data. Referring to an example in <FIG>, identification memory <NUM> stores an ISO <NUM>/<NUM> telegram and its content is continuously transmitted by the transponder whenever the transponder is activated. The authentication memory <NUM> stores the authentication data and its content is only transmitted by the transponder, in general, once every time a memory read command is received by the transponder. In certain instances, multiple read commands may be needed to retrieve a complete authentication. A conventional scanner without authentication capabilities will follow the conventional identification process flow shown in <FIG> and only have access to the ISO telegram stored in the identification memory <NUM>.

In the example implementation shown in <FIG>, the signature <NUM> is stored in a baseline configuration. In the baseline signature storage format shown in <FIG>, the complete signature <NUM> is stored in the internal memory <NUM> of the transponder with no part of it appearing in the telegram <NUM> shown in <FIG>. To retrieve the complete signature <NUM>, the RFID scanner has to transmit memory read commands <NUM> to the transponder, as shown in <FIG>.

Referring to <FIG>, for the implementation shown in <FIG>, a signature indicator <NUM> can be introduced to the user information field <NUM> of an identification code <NUM> specified in the ISO <NUM>:<NUM>/Amd. <NUM>:<NUM> standard.

In some implementations, at least part of a signature can be stored as part of the identification data. For example, referring to <FIG>, a signature <NUM> & <NUM> is stored in a partial signature trailer configuration. In the partial-signature trailer format shown here, a portion of the signature is stored in the telegram trailer <NUM>. The telegram trailer <NUM>, shown in <FIG>, is transmitted as a part of the ISO <NUM>/<NUM> telegram <NUM>. All standard conforming scanners can read and collect this part of the signature during the conventional transponder scanning process shown in <FIG>. In particular, at the start of a scan (<NUM>), the scanner send an activation signal (<NUM>) which causes the transponder to transmit the default telegram <NUM>. The scanner receives and reads the telegram (<NUM>). This completes the scan (<NUM>). The transponder is switched off when the activation field is no longer present.

The remaining portion of the signature <NUM> is stored in the internal memory <NUM> of the transponder. To retrieve the complete signature <NUM> & <NUM>, the RFID scanner has to transmit memory read commands <NUM> to the transponder, as shown in <FIG>.

While the foregoing example features a portion of the signature is stored in the telegram trailer <NUM>, other configurations are possible. For example, in some embodiments, part of the signature can be stored in the telegram's identification code. <FIG> shows an implementation of a telegram's identification code <NUM> in which part of the signature is included in user information field <NUM>. In some embodiments, an authentication signature generated from the transponder UID <NUM> and the animal identification number <NUM> is introduced to every transponder for authentication. A scanner can validate the authenticity of the signature by using the animal identification number <NUM>, a known public key, and the transponder UID <NUM> as the input parameters to the validation function.

As further shown in <FIG>, to authenticate a signed transponder, the RF scanner has to perform additional data extraction <NUM>, <NUM> and transponder interrogation <NUM>. After completing the operations <NUM>, <NUM>, <NUM>, and <NUM> corresponding to the identification process shown in <FIG> (i.e., operations <NUM>, <NUM>, <NUM>, and <NUM>), the scanner attempts to detect <NUM> a signature indicator <NUM> in the telegram <NUM>/<NUM>'s user information field <NUM>. The absence 505N of a signature indicator <NUM> immediately categorizes <NUM> the transponder as "not signed". No authentication is possible for such transponders. This is the case for existing conventional ISO transponders in the market.

If a signature indicator <NUM> is detected 505Y, the scanner will extract <NUM> the partial signature from the telegram trailer <NUM> for signed transponders using the partial signature trailer <NUM> storage configuration. Afterwards, the scanner reads the transponder UID <NUM> and the remaining signature data <NUM>, <NUM> from the transponder by sending multiple memory read commands <NUM>. When both the transponder UID <NUM> and the complete signature <NUM>, <NUM> & <NUM> are collected via UID and signature data transmission <NUM> from the transponder, the scanner can validate <NUM>, <NUM> the signature stored in the transponder using the public key, the identification code <NUM>, and the transponder UID <NUM> as decryption parameters. The validation process described above is shown in <FIG>. When validating, the UID and signature read orders can be interchanged.

<FIG> is a flowchart of a programming process of a conventional ISO transponder. To produce the conventional transponder, an ISO <NUM>/<NUM> compliant programmer starts <NUM> with data collection <NUM> including obtaining an identification code <NUM> from programmer memory. The programmer writes the transponder configuration <NUM>, the telegram <NUM>, and the transponder lock <NUM> in the sequence to transponder in a telegram write (<NUM>), configuration write (<NUM>) and lock (<NUM>) steps, as shown in <FIG>. The production of signed transponders requires additional steps to interrogate the transponder <NUM> and compute the signature <NUM>.

<FIG> is a flowchart of a programming process of a signed transponder, in accordance with the disclosed technologies. For a signed transponder, the programmer needs the additional steps of reading the UID of the transponder <NUM> and generating the authentication signature <NUM> before programming both the telegram and the signature <NUM>. For a public-key based authentication signature, the programmer uses a private key, the transponder UID <NUM>, the identification code <NUM>, and a random salt as parameters for signature generation <NUM>. With the signature generated, the programmer can then write the configuration <NUM>, the telegram <NUM>, the signature <NUM>, and the lock configuration <NUM> to the transponder in the sequence shown in <FIG>. Steps in the process shown in <FIG> that are common to the process shown in <FIG> have like labels, advanced by <NUM>. , in <FIG> the process starts at <NUM>, in <FIG> the process starts at <NUM>. When programming, the configuration and telegram write orders can be interchanged.

In summary, this specification describes means for manufacturers to produce ISO <NUM>/<NUM> compliant transponders with authentication signature using commonly available transponders and RFID programmers. This specification also describes a method to validate the authentication signature using RFID scanners with transponder programming features.

Claim 1:
A radio frequency identification, RFID, transponder (<NUM>), comprising:
a radio frequency, RF, transceiver (<NUM>); and
memory (<NUM>) in communication with the RF transceiver, the memory storing data retrievable by a scanner via the RF transceiver, the memory being programmed according to ISO <NUM>/<NUM> code structures and comprising:
(i) read-only memory (<NUM>) comprising a unique identification, UID, code unique to the transponder, wherein the RFID transponder is programmed to transmit the UID code upon receiving a UID-read signal by the transponder;
(ii) field-programmable memory (<NUM>) comprising a default RFID telegram comprising a sequence of data continuously transmitted by the transponder automatically upon activation of the transponder by the scanner, the default RFID telegram comprising data identifying an animal associated with the transponder; and
(iii) field-programmable memory comprising an encrypted signature generated by encrypting a signature comprising the default RFID telegram and the UID code using a public-private key encryption scheme, the RFID transponder being programmed to transmit the encrypted signature upon receipt of a memory-read signal by the transponder,
wherein the RFID transponder is compliant with ISO <NUM>/<NUM> code structures.