Cryptographic lock, method of operation thereof and secure container employing the same

• US 8,907,794 B2
• Filed: 05/30/2008
• Issued: 12/09/2014
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Estevez, Leonardo W., Varghese, Johnsy, Lazar, Steven C.
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): ALAM, MIRZA F
• Application Number:
  US12/130,315
• Publication Number:
  US 20090322531A1
• Time in Patent Office: 2,384 Days
• Field of Search: 340/572.1, 340/572.8, 340/572.9, 340/870.01, 340/531, 340/693.9, 340/539.12, 340/539.13, 340/539.26, 340/572.4, 702/56, 702/33, 702/185, 702/188, 604/20, 604/65, 604/66, 604/67, 604/890.1, 604/892, 604/892.1
• US Class Current: 340/572.1
• CPC Class Codes: E05B 47/0009 with thermo-electric actuators, e.g. heated bimetals
• CPC Class Codes: G07C 2209/08 With time considerations, e.g. temporary activation, valid time window or time limitations
• CPC Class Codes: G07C 9/00896 specially adapted for particular uses
• CPC Class Codes: Y10T 70/5004 For antitheft signaling device on protected article

Abstract

Various cryptographic locks for securing assets, secure containers and methods of operating a cryptographic lock. One embodiment of a cryptographic lock includes: (1) a shape memory alloy (SMA) having a first and second phase, wherein the first phase inhibits access to an asset and the second phase allows access to the asset and (2) an RFID transponder, coupled to the SMA, configured to receive an authentication signal from an RFID transceiver and, based thereon, energize the SMA to temporarily change the SMA from the first phase to the second phase.

Claims

1. A cryptographic lock for securing an asset, comprising:

a shape memory alloy (SMA) having a first and second phase, said first phase inhibiting access to an asset and said second phase allowing access to said asset;

wherein said first phase is a Martensite phase of said SMA and said second phase is an Austenite phase of said SMA; and

an RFID transponder, coupled to said SMA, configured to receive an authentication signal from an RFID transceiver and, based thereon, energize said SMA to temporarily change said SMA from said first phase to said second phase,

wherein said cryptographic lock secures said asset within a cavity of a body of a secure container, said secure container further having a lid secured by said cryptographic lock through employment of said first phase,

wherein said RFID transponder is a Near Field Communication (NFC) transponder,

wherein said RFID provides current to the SMAs to energize the SMA the through the heat generated by the current provided to the SMA, transform the SMA , from the Martensite phase and to the Austenite phase,

wherein said RFID transponder generates about 1.8 mA at about 2 volts for said SMA upon receipt of said authentication signal, and

wherein said 1.8 mA at about 2 volts has been captured or redirected by the RFID transponder to transform the SMA.

2. The cryptographic lock as recited in claim 1 wherein said SMA is a first SMA, said cryptographic lock further comprising a second SMA having a first and second phase, said first phase inhibiting access to said asset and said second phase allowing access to said asset.

3. The cryptographic lock as recited in claim 2 wherein said RF transponder is coupled to said second SMA and is configured to energize said second SMA based on receipt of said authorization signal to temporarily change said second SMA from said first phase to said second phase.

4. The cryptographic lock as recited in claim 2 wherein said RF transponder is a first RF transponder, said cryptographic lock further including a second RF transponder coupled to said second SMA and configured to energize said second SMA based on receipt of another authorization signal to temporarily change said second SMA from said first phase to said second phase.

5. A method of operating a cryptographic lock having at least one shape memory alloy (SMA), comprising:

receiving a first RF signal;

determining said first RF signal includes a first designated key; and

energizing, if said first RF signal includes said first designated key, a first SMA to change said first SMA from a first phase to a second phase, said first phase inhibiting access to an asset and said second phase allowing access to said asset,

wherein said first phase is a Martensite phase of said SMA and said second phase is an Austenite phase of said SMA; and

wherein said cryptographic lock secures said asset within a cavity of a body of a secure container, said secure container further having a lid secured by said cryptographic lock through employment of said first phase,

wherein said RF signal is a Near-Field Communication (NFC) signal received by an RFID transponder, and

wherein said RFID provides current to the SMAs to energize each SMA the through the heat generated by the current provided to the SMA, transform the SMA, from the Martensite phase and to the Austenite phase,

wherein said RFID transponder generates about 1.8 mA at about 2 volts for said SMA upon receipt of said authentication signal, and

wherein said 1.8 mA at about 2 volts has been captured or redirected by the RFID transponder.

6. The method as recited in claim 5 wherein said energizing includes generating current to traverse said SMA and cause said SMA to transform from said Martensite phase to said Austenite phase.

7. The method as recited in claim 5 further comprising receiving a second RF signal, determining said second RF signal includes a second designated key and energizing, if said second RF signal includes said second designated key, a second SMA to change said second SMA from a first phase to a second phase, said first phase inhibiting access to said asset and said second phase allowing access to said asset, wherein said second RF signal, designated key and SMA differ from said first RF signal, designated key and SMA.

8. The method as recited in claim 5 wherein said energizing includes energizing a second SMA to change said second SMA from a first phase to a second phase, said first phase inhibiting access to an asset and said second phase allowing access to said asset.

9. A secure container, comprising:

a body having a cavity;

a lid configured to engage said body and cover at least a portion of said cavity; and

a cryptographic lock associated with one of said body and said lid, said cryptographic lock including;

a shape memory alloy (SMA) capable of assuming an Austenite phase and a Martensite phase, one of said Austenite phase and said Martensite phase being a first phase and another of said Austenite phase and said Martensite phase being a second phase, said first phase inhibiting said lid from uncovering said cavity, said second phase allowing said lid to be displaced to uncover said cavity, and

an RFID transponder, coupled to said SMA, configured to receive an authentication signal from an RFID transceiver and, based thereon, energize said SMA and thereby temporarily cause said SMA to change from said first phase to said second phase.

wherein said cryptographic lock secures an asset within said cavity of said secure container through employment of said lid, said lid secured by said cryptographic lock through employment of said first phase,

wherein said RFID transponder is a Near Field Communication (NFC) transponder,

wherein said RFID provides current to the SMAs to energize each SMA the through the heat generated by the current provided to the SMA, transform the SMA , from the Martensite phase and to the Austenite phase,

wherein said RFID transponder generates about 1.8 mA at about 2 volts for said SMA upon receipt of said authentication signal, and

wherein said 1.8 mA at about 2 volts has been captured or redirected by the RFID transponder.

10. The secure container as recited in claim 9 wherein said SMA is a first SMA, said cryptographic lock further comprising a second SMA having a first and second phase, said first phase inhibiting access to said asset and said second phase allowing access to said asset.

11. The secure container as recited in claim 10 wherein said RF transponder is coupled to said second SMA and is configured to energize said second SMA based on receipt of said authorization signal to temporarily change said second SMA from said first phase to said second phase.

12. The secure container as recited in claim 10 wherein said RF transponder is a first RF transponder, said cryptographic lock further including a second RF transponder coupled to said second SMA and configured to energize said second SMA based on receipt of another authorization signal to temporarily change said second SMA from said first phase to said second phase.

13. A cryptographic lock for securing an asset, comprising:

a shape memory alloy (SMA) having a first and second phase,

wherein said first phase is a Martensite phase of said SMA and said second phase is an Austenite phase of said SMA; and

an RFID transponder, coupled to said SMA, configured to receive an authentication signal from an RFID transceiver and, based thereon, energize said SMA to temporarily change said SMA from said first phase to said second phase,

wherein said cryptographic lock secures said asset within a cavity of a body of a secure container, said secure container further having a lid secured by said cryptographic lock through employment of said first phase;

said SMA configured as a first latch configured to inhibit access to an asset when in a locked position and allow access to said asset when in an unlocked position, wherein said first latch is configured to temporarily change from said locked position to said unlocked position in response to receipt of an RF signal at a first frequency,

the cryptographic lock further comprising an RF transponder coupled to said first latch and configured to receive said RF signal and energize said first latch to cause said first latch to move from said locked position to said unlocked position, wherein said RF transponder is an RFID transponder, and wherein said RFID transponder is a Near Field Communication (NFC) transponder,

and wherein said RFID provides current to the SMAs to energize each SMA the through the heat generated by the current provided to the SMA, transform the SMA , from the Martensite phase and to the Austenite phase,

wherein said RFID transponder generates about 1.8 mA at about 2 volts for said SMA upon receipt of said authentication signal, and

wherein said 1.8 mA at about 2 volts has been captured or redirected by the RFID transponder.

14. The lock as recited in claim 13 further comprising a second latch configured to inhibit access to said asset when in a locked position and allow access to said asset when in an unlocked position, wherein said second latch is configured to temporarily change from said locked position to said unlocked position in response to receipt of an RF signal at a second frequency different from said first frequency.

15. The lock as recited in claim 13 wherein said first latch is a shape metal alloy.

16. The lock as recited in claim 13 wherein said first latch is a solenoid.