Tamper Evident Seal System and Method

• US 20060195705A1
• Filed: 02/27/2006
• Published: 08/31/2006
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Cypak AB
• Inventors: Ehrensvard, Jakob, Einberg, Fredrik
• Granted Patent: US 7,772,974 B2
• Time in Patent Office: Days
• US Class Current: 713/194
• CPC Class Codes: B65D 2203/10 Transponders
• CPC Class Codes: B65D 5/4233 Cards, coupons, labels or the like formed separately from the container or lid
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/0637 Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H05K 1/0268 for electrical inspection or testing
• CPC Class Codes: H05K 1/0275 Security details, e.g. tampering prevention or detection
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/10151 Sensor

Abstract

A tape seal includes electronic circuitry to detect tamper- and manipulation events relating to sealed items in various embodiments. A complex impedance is formed in a continuous seal. The seal is designed in such a way, that any attempt to break or remove the seal results in a change of the complex impedance. An electronic module in connection with the seal quantifies a complex impedance, and when a change is detected above a programmed threshold, this is treated as a tamper event. In one embodiment, the inclusion of reference impedances are applied to allow a more precise detection of a tamper event and allow for automatic calibration of natural variations of the complex impedance. In a further embodiment, a method of determining tampering with a sealed item is disclosed.

Claims

1. A tape seal for sealing an item and allowing for detection of tampering with the seal, the tape seal comprising:

a substrate having an integral and electrically conductive circuit arrangement and a detection circuit,

wherein said detection circuit monitors a complex impedance of said conductive circuit arrangement and, responsive to the monitored complex impedance, detects tampering with the tape seal;

a radio telemetry interface operatively coupled to said electronic detection circuit so as to allow information to be exchanged between the tape seal and an external host computer system.

2. The tape seal of claim 1, wherein said conductive circuit arrangement comprises circuit lines of printed electrically conductive ink.

3. The tape seal of claim 2, wherein said substrate is selected from the group consisting of a polymer, a paper, and a combination thereof.

4. The tape seal of claim 2, wherein said electrically conductive circuit arrangement comprises at least one circuit line adapted and arranged so that tampering with the tape seal causes a change of resistance of said circuit line,

wherein said change of resistance of said circuit line is recorded and stored by the detection circuit.

5. The tape seal of claim 4, wherein the at least one circuit line comprises plural circuit lines each having a different length corresponding to associated visual markings on the tape seal so that the tape seal may suitably be cut at different lengths.

6. The tape seal of claim 2, wherein said electrically conductive circuit arrangement comprises at least one resistive circuit line in series with at least one capacitive circuit element,

wherein a resulting complex impedance is monitored by the detection circuit and a change in the complex impedance is recorded as a tamper event by the detection circuit.

7. The tape seal of claim 6, further comprising a pair of electrically conductive tape elements, each of said tape element having one end thereof connected to the detection circuit and the other end arranged so as to at least partially overlap the other tape element in the pair,

wherein said pair of electrically conductive tape elements are arranged by said overlap so as to form a capacitive circuit element when the tape seal is mounted on the item.

8. The tape seal of claim 7, wherein the detection circuit comprises an electronic module mounted on the item and connected to the conductive circuit arrangement,

wherein the electronic module is mounted separately at least from the conductive circuit arrangement.

9. The tape seal of claim 8, wherein said electronic module is connected to the conductive circuit arrangement via a capacitive connection.

10. The tape seal of claim 1, wherein the conductive circuit arrangement comprises an electrically conductive film.

11. The tape seal of claim 1, further comprising a reference circuit adapted and arranged to calibrate the detection circuit to account for changes in the sensing circuit arrangement.

12. A method of detecting tampering with a sealed item, the method comprising:

placing the sealed item in proximity to device comprising an RFID scanner;

transmitting a unique identity to a host from the device;

retrieving an appropriate cryptographic key from a host database to be used for secure operations with the device;

challenging the device by the host;

transmitting encrypted data from the device to the host; and

receiving and decrypting the encrypted data in the host,

wherein the device transmits encrypted data to the host in a chain-blocked-cipher (CBC) mode.

13. The method of claim 12, wherein a first transmitted block includes a linear counter and a time reference to ensure that two subsequent transmissions of the same data is different so as to thwart a security attack involving comparing data.

14. The method of claim 12, wherein a final block comprises a known signature that allows the host to determination that all transmitted data has been successfully received.

15. The method of claim 12, wherein the host decrypts the encrypted data and verifies a signature in a last block to ensure that received data was authentically received without errors.

16. The method of claim 12, wherein the host performs an operation on the data and returns a completion message to the device.

17. The method of claim 12, further comprising, after said step of transmitting a unique identity to a host from the device, receiving a challenge from the host,

wherein the device encrypts the challenge together with said unique identity and sends back an encrypted result as a response.

18. The method of claim 12, further comprising the host requesting data from the device and initiating the CBC encryption by sending an Initialization Vector to prevent any attempt to replay previously transmitted data.

19. The method of claim 12, wherein the host is resident on a network.

20. A method of detecting tampering with a seal, the method comprising:

placing the sealed item in proximity to device including a radio-telemetry scanner;

transmitting a unique identity to a host in clear text;

performing, by a host, a search in a database to get an appropriate cryptographic key suitable for use in secure operations with the device;

issuing, by the host, a random number which is transmitted to the device as a challenge;

encrypting a challenge, together with the unique identity, and sending the result as a response to the host;

decrypting, by the host, a received response and authenticating that the decrypted result matches the issued challenge and the initial received identity and that the device is authentic;

requesting data from the device, and initiating a Chained Block Cipher (CBC) encryption by sending an Initialization Vector (IV), wherein the initialization vector prevents attempts to replay previously transmitted data;

transmitting, by the device, data to the host, encrypted in the CBC mode, wherein a first transmitted block includes a linear counter and a time reference, if applicable, to make two subsequent transmissions for the same data guaranteed different, thereby thwarting attacks involving comparing data,

wherein the final block comprises a known signature including a device identity padded with zeroes, thereby allowing the host to detect that all data has been received successfully;

receiving and decrypting the received data by the host;

verifying that a signature in a last block to ensure that the received data was authentically received and without errors; and

performing, by the host, necessary operations on the data and returning a suitable completion message to the device.