METHOD FOR SHARING A LINK KEY IN A ZIGBEE NETWORK AND A COMMUNICATION SYSTEM THEREFOR

• US 20090177889A1
• Filed: 12/04/2008
• Published: 07/09/2009
• Est. Priority Date: 12/04/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: SUNG, Yeul-Tak, Kim, Jae-Ho, Han, Young-Seop
• Granted Patent: US 8,295,489 B2
• Time in Patent Office: Days
• US Class Current: 713/171
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 2463/062 applying encryption of the keys
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys

Abstract

A communication system and method for securely and efficiently sharing a link key for security and authentication in a ZigBee network. Upon receipt of an access request from an end device, a trust center sends a public key to the end device, and upon receipt of the public key, the end device encrypts an arbitrary key using the public key, and sends the encrypted arbitrary key to the trust center. The trust center generates a link key using the arbitrary key, and sends the link key to the end device.

Claims

1. An end device for sharing a link key in a ZigBee network, the end device comprising:

a ZigBee communication module for sending an access request to a trust center, and receiving a public key from the trust center;

a key generator for generating an arbitrary key; and

a key calculator for encrypting the arbitrary key using the received public key.

2. The end device of claim 1, wherein the ZigBee communication module receives the link key encrypted with the arbitrary key from the trust center and the key calculator decodes the link key using the arbitrary key.

3. A trust center for sharing a link key in a ZigBee network, the trust center comprising:

a memory for storing a public key and a private key corresponding to the public key;

a ZigBee communication module for sending the public key to an end device when an access request is received from the end device, and receiving an encrypted arbitrary key from the end device;

a key calculator for decoding the arbitrary key encrypted with the public key using the private key; and

a key generator for generating the link key for the end device using the decoded arbitrary key.

4. The trust center of claim 3, wherein the key calculator encrypts the generated link key using the decoded arbitrary key and a ZigBee communication module sends the encrypted link key to the end device.

5. A method for sharing a link key by an end device in a ZigBee network, the method comprising:

sending an access request to a trust center;

receiving a public key from the trust center;

generating an arbitrary key, and encrypting the arbitrary key using the public key;

sending the encrypted arbitrary key to the trust center;

receiving an encrypted link key from the trust center; and

decoding the encrypted link key using the arbitrary key.

6. The method of claim 5, further comprising:

receiving a first link key from the trust center;

generating a hash function using the received first link key;

encrypting a second authentication data using the generated hash function;

transmitting a first authentication data and the encrypted second authentication data to the trust center;

receiving another second authentication data from the trust center;

determining whether the received another second authentication data is identical to the second authentication data;

when the received another second authentication data is identical to the second authentication data, sending an authentication confirm response to the trust center;

receiving a second link key and a network key from the trust center; and

performing a ZigBee communication using the received second link key and network key.

7. The method of claim 6, wherein encrypting the second authentication data comprises:

encrypting the second authentication data using the hash function to generate first hash data; and

encrypting the second authentication data using the first hash data to generate second hash data.

8. The method of claim 6, wherein encrypting the hash function using second authentication data comprises:

encrypting the second authentication data using the first link key and a CCM* (Enhanced counter with Cipher Block Chaining-Message Authentication Code (CBC-MAC) mode of operation).

9. The method of claim 6, further comprising:

when the received another second authentication data is not identical to the second authentication data, closing a connection to the trust center.

10. A method for sharing a link key by a trust center in a ZigBee communication network, the method comprising:

receiving an access request from an end device;

sending a stored public key to the end device;

receiving an arbitrary key encrypted with the public key from the end device;

decoding the encrypted arbitrary key using a private key associated with the public key;

generating a link key using the decoded arbitrary key;

encrypting the generated link key using the decoded arbitrary key; and

sending the encrypted link key to the end device.

11. The method of claim 10, further comprising:

receiving first authentication data for the end device and encrypted second authentication data;

determining if the end device is an authorized user, depending on the first authentication data and the encrypted second authentication data; and

when the end device is an authorized user, generating a new link key and a network key, and sending the new link key and the network key to the end device.

12. The method of claim 11, further comprising:

closing a connection to the end device when the end device is not the authorized user.

13. The method of claim 11, wherein the first authentication data is a phone number or a serial number of the end device.

14. The method of claim 11, wherein the second authentication data is a Mobile Identification Number (MIN) of the end device.

15. The method of claim 11, wherein determining if the end device is the authorized user comprises:

determining if the first authentication data has been received from the end device;

when the first authentication data has been received, determining if the received first authentication data is identical to stored first authentication data;

when the received first authentication data is identical to the stored first authentication data, determining if the encrypted second authentication data has been received from the end device;

when the encrypted second authentication data has been received, decoding the encrypted second authentication data;

determining if the decoded second authentication data is identical to stored second authentication data; and

when the decoded second authentication data is identical to the stored second authentication data, transmitting the stored second authentication data to the end device.

16. The method of claim 15, further comprising:

closing a connection to the end device when the first authentication data is not received.

17. The method of claim 15, further comprising:

closing a connection to the end device when the received first authentication data is not identical to the stored first authentication data.

18. The method of claim 15, further comprising:

when the encrypted second authentication data is not received, notifying the end device that the end device has been registered.

19. The method of claim 15, further comprising:

when the decoded second authentication data is not identical to the stored second authentication data, closing a connection to the end device.

20. The method of claim 11, further comprising:

receiving an authentication confirm response from the end device before generating the new link key and the network key.

21. A trust center for sharing a link key in a ZigBee network, the trust center comprising:

a key generator for generating the link key and a network key;

a key calculator for encrypting the link key and the network key generated by the key generator, and decoding encrypted keys received from an end device;

a ZigBee communication module for performing ZigBee communication with the end device; and

a controller for controlling to send a stored public key to the end device upon receipt of an access request from the end device, to receive an encrypted arbitrary key using the public key from the end device, to decode the encrypted arbitrary key using a stored private key corresponding to the public key, to generate a link key using the decoded arbitrary key, to encrypt the generated link key using the decoded arbitrary key, and to send the encrypted link key to the end device.

22. The trust center of claim 21, wherein the controller controls to receive first authentication data or encrypted second authentication data for the end device from the end device, to determine if the end device is an authorized user depending on the first authentication data and the encrypted second authentication data, to generate a new link key and a network key when the end device is an authorized user, and to send the new key and the network key to the end device.

23. The trust center of claim 22, wherein the controller controls to close a connection to the end device when the end device is not the authorized user according to result of the determination.

24. The trust center of claim 22, wherein the first authentication data is a phone number or a serial number of the end device.

25. The trust center of claim 22, wherein the second authentication data is a Mobile Identification Number (MIN) of the end device.