Key and lock device

• US 7,099,474 B1
• Filed: 05/05/2000
• Issued: 08/29/2006
• Est. Priority Date: 05/06/1999
• Status: Expired due to Term

• Current Assignee: Assa Abloy AB
• Original Assignee: Assa Abloy AB
• Inventors: Lefebvre, Arnaud, Magnusson, Björn, Hammer, Walter, Andre, Gilbert, Thomas, J M, Jaquet, Claude-Eric, Krühn, Jürgen, Brennecke, Gudrun, Warnström, Johan, Hakkarainen, Reijo, Darmanin, Christian, Schoell, Lance, Sivonen, Hannu, Norberg, Rolf, Lidén, Inge, Peguiron, Nicolas, Chanel, Christophe, Varenne, Alain, Gürtler, Jens
• Primary Examiner(s): ARANI, TAGHI T
• Application Number:
  US09/565,495
• Time in Patent Office: 2,307 Days
• Field of Search: 380/262, 340/5.1, 340/5.6, 340/5.7, 340/5.74, 340/500, 340/825.31, 235/382, 713/168, 713171-173
• US Class Current: 380/262
• CPC Class Codes: G07C 2009/00404 starting with prompting the lock
• CPC Class Codes: G07C 2009/00412 the transmitted data signal being encrypted
• CPC Class Codes: G07C 2009/005 whereby the code is a random code
• CPC Class Codes: G07C 2009/00587 by battery
• CPC Class Codes: G07C 2009/00761 with data transmission performed by connected means, e.g. mechanical contacts, plugs, connectors
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

A key and lock device comprises a key having a first electronic circuit and a lock having a second electronic circuit. The key and the lock store secret information, some of which is unique for each device. The key and the lock exchange a random number through connectors and perform a calculation in the respective circuitry based on the random number and secret information. An electrical blocking mechanism is moved to a non-blocking position if a comparison of the calculations in the circuits gives the correct result.

Claims

1. A key and lock device having a key and a lock, comprising:

a plurality of first devices belonging to a group of first devices, each first device comprising;

a first electronic processor,

a first memory connected to said first electronic processor, and

a first connector connected to said first electronic processor,

a second device comprising;

a second electronic processor,

a second memory connected to said second electronic processor, and

a second connector connected to said second electronic processor and adapted to mechanically co-operate with said first connector when said key is inserted in the lock so as to transfer information between said key and lock, and

a power source connectable to said first and second processors,

a mechanically operated blocking mechanism operated by a mechanically coded device, and

an electrically operated blocking mechanism adapted to block operation of the lock when an unauthorized key is inserted in the lock, wherein

said first memory is adapted for storing a public identity and a single secret identity, wherein said secret identity is the same for the first devices belonging to the group of first devices,

said second memory is adapted for storing the public identity and a secret identity for authorized first devices,

said first electronic processor is arranged to identify itself to said second electronic processor by said public identity, and

said first and second electronic processors are arranged to exchange a random number and to calculate a respective code word using at least a part of said secret identity and at least a part of said random number, and

wherein said electrically operated blocking mechanism is brought to a non-blocking position if said code words calculated in said first and second electronic circuits, respectively, are identical.

2. The key and lock device according to claim 1, wherein said first devices are keys and said second device is a lock.

3. The key and lock device according to claim 1, wherein said first devices are locks and said second device is a key.

4. The key and lock device according to claim 1, wherein said first and second electronic processors are arranged to encrypt said code word before communication thereof.

5. The key and lock device according to claim 4, wherein said code word is encrypted by means of at least a part of a DES encryption key.

6. The key and lock device according to claim 4, wherein said code word is encrypted by means of at least a part of said secret identity.

7. The key and lock device according to claim 4, wherein said code word is encrypted by means of at least a part of said random number.

8. The key and lock device according to claim 4, wherein there is no operation for reading of secret information.

9. The key and lock device according to claim 1, wherein said first and second electronic processors are identical regarding their hardware design.

10. The key and lock device according to claim 1, comprising at least one tamper proof memory.

11. The key and lock device according to claim 10, wherein said secret identity is stored in a tamper proof memory.

12. The key and lock device according to claim 2, wherein said first connector is provided at the end of the key bit of the key.

13. The key and lock device according to claim 2, wherein said first connector is provided on an edge of a grip part of the key to cooperate with a connector on an outer surface of the lock.

14. The key and lock device according to claim 1, wherein the power source is provided in the key.

15. The key and lock device according to claim 1, wherein the power source is provided in the lock.

16. The key and lock device according to claim 1, wherein said first and second connectors are adapted for transferring electrical power.