Method of distributing encryption keys among nodes in mobile ad hoc network and network device using the same

• US 20040228492A1
• Filed: 05/14/2004
• Published: 11/18/2004
• Est. Priority Date: 05/16/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Kyung-bae
• Granted Patent: US 7,760,885 B2
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• 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 63/0869 for achieving mutual authentication cryptographic mechanisms or cryptographic arrangements for mutual authentication H04L9/3273
• 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 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/3013 involving the discrete logarithm problem, e.g. ElGamal or Diffie-Hellman systems

Abstract

A method of distributing encryption keys among nodes in a mobile ad hoc network, and a network device using the same. In particular, e a method of distributing encryption keys, which guarantees the security of a ciphertext in the mobile ad hoc network. The method of distributing the encryption keys among nodes including a first node and a second node in the mobile ad hoc network include creating a private key and a public key based on a first encryption method by the first node; if the first node transmits the created public key to Node B, creating predetermined parameters operable to create a common key according to a second encryption method by the second node.

Claims

1. A method of distributing encryption keys among nodes in a mobile ad hoc network, comprising:

creating a private key and a public key based on a first encryption method by a first node;

transmitting, by the first node, the created public key to a second node and receiving a ciphertext transmitted from the second node and decrypting the received ciphertext by using a private key of the first node; and

creating, by the first node, a private key and a public key based on a second encryption method by using the decrypted ciphertext, encrypting the public key based on the second encryption method with the public key based on the first encryption method, and then transmitting the encrypted public key to the second node.

2. The method as claimed in claim 1, wherein the first encryption method comprises a public key encryption method.

3. The method as claimed in claim 2, wherein the ciphertext is encrypted with the public key of the first node based on the first encryption method and comprises predetermined parameters comprising the public key of the second node based on the first encryption method, global public elements based on the second encryption method and the public key of the second node based on the second encryption method.

4. The method as claimed in claim 1, wherein when the public key of the first node based on the second encryption method is encrypted and transmitted to the second node, the public key of the first node is encrypted with the public key of the second node created by the first encryption method through the decrypted ciphertext.

5. The method as claimed in claim 1, wherein the second encryption method comprises the Diffie-Hellman encryption method, and the distribution method further comprises creating a common key by using the private key of the first node based on the Diffie-Hellman encryption method and the public key of the second node created by the Diffie-Hellman encryption method through the ciphertext.

6. A method of distributing encryption keys among nodes in a mobile ad hoc network, comprising:

if a second node receives a public key of a first node based on a first encryption method from the first node, creating predetermined parameters operable to create a common key according to a second encryption method by the second node;

encrypting, by the second node, the created, predetermined parameters with the received public key of the first node and transmitting the encrypted parameters to the first node; and

receiving a ciphertext transmitted from a first node and decrypting the received ciphertext by using the private key of the second node.

7. The method as claimed in claim 6, wherein the predetermined parameters comprise the public key of the second node based on the first encryption method, global public elements based on the second encryption method, and the public key of the second node based on the second encryption method.

8. The method as claimed in claim 6, wherein the first encryption method comprises a public key encryption method.

9. The method as claimed in claim 8, wherein the ciphertext is encrypted with the public key of the second node based on the first encryption method.

10. The method as claimed in claim. 6, wherein the second encryption method comprises a Diffie-Hellman encryption method, and the distribution method further comprises creating the common key using the public key of the first node created by the Diffie-Hellman encryption method through decrypted ciphertext and the private key of the second node based on the Diffie-Hellman encryption method.

11. A method of distributing encryption keys among nodes in a mobile ad hoc network, comprising:

creating a private key and a public key based on a first encryption method by a first node;

if the first node transmits the created public key based on the first encryption method to a second node, creating predetermined parameters operable to create a common key according to a second encryption method by the second node;

if the second node encrypts the created, predetermined parameters with the public key based on the first encryption method and transmits the encrypted parameters as a ciphertext to the first node, decrypting the received ciphertext by using the private key of the first node by the first node;

creating, by the first node, a private key and a public key based on a second encryption method by using the decrypted ciphertext, encrypting the created public key based on the second encryption method and transmitting the encrypted public key as a ciphertext to the second node; and

receiving, by the second node, the ciphertext transmitted from the first node and decrypting the received ciphertext by using the private key of the second node.

12. The method as claimed in claim 11, wherein the predetermined parameters comprise the public key of the second node based on the first encryption method, global public elements based on the second encryption method, and the public key of the second node based on the second encryption method.

13. The method as claimed in claim 11, wherein the first encryption method comprises a public key encryption method.

14. The method as claimed in claim 11, wherein the second encryption method comprises the Diffie-Hellman encryption method, and

the distribution method further comprises:

creating, by the first node, the common key by using the private key of the first node based on the Diffie-Hellman encryption method and the public key of the second node created Diffie-Hellman encryption method through the decrypted parameters; and

creating, by the second node, the common key by using the private key of the first node created by the Diffie-Hellman encryption method through the ciphertext, which has been decrypted with the private key of the second node, and the private key of the second node based on the Diffie-Hellman encryption method.

15. A network device, comprising:

an encryption unit operable to transmit a public key of a first node based on a first encryption method to a second node in a mobile ad hoc network, decrypting a ciphertext transmitted from the second node by using a private key of the first node and the first node creating a private key and a public key based on a second encryption method by using the decrypted ciphertext, and encrypting the public key of the first node based on the second encryption method by using the public key based on the first encryption method and transmitting the encrypted public key to the second node; and

an information storage unit operable to store information required or created operable to perform encryption and decryption through the encryption unit.

16. The device as claimed in claim 15, further comprising a transmitting/receiving unit operable to enable the transmission/reception of information through a communication link connected to the first node or the second node in the mobile ad hoc network, and an application driving unit operable to control the operation of providing applications according to information obtained through a decryption procedure performed in the encryption unit.

17. The device as claimed in claim 15, wherein the ciphertext is encrypted by using the public key of the first node based on the first encryption method and comprises predetermined parameters consisting of the public key of the second node based on the first encryption method, global public elements based on the second encryption method and the public key of the second node based on the second encryption method.

18. The device as claimed in claim 15, wherein the first encryption method comprises a public key encryption method, and when the public key of the first node based on the second encryption method is encrypted and transmitted to the second node, the public key of the first node is encrypted with the public key of the second node created by the first encryption method through the decrypted ciphertext.

19. The device as claimed in claim 15, wherein the second encryption method comprises the Diffie-Hellman encryption method, and a common key is created by using the private key of the first node based on the Diffie-Hellman encryption method and the public key of the second node created by the Diffie-Hellman encryption method through the ciphertext.

20. A network device, comprising:

an encryption unit operable to create predetermined parameters operable to be used in creating a common key according to a second encryption method when a public key based on a first encryption method is received from a first node in a mobile ad hoc network, encrypting the created parameters with the public key based on the first encryption method, transmitting the encrypted parameters to the first node, and decrypting a ciphertext transmitted from the first node by using the private key of the first node; and

an information storage unit operable to store information required or created operable to perform encryption and decryption through the encryption unit.

21. The device as claimed in claim 20, further comprising a transmitting/receiving unit operable to enable the transmission/reception of information through a communication link connected to a specific node in the mobile ad hoc network, and an application driving unit operable to control the operation of providing applications according to information obtained through a decryption procedure performed in the encryption unit.

22. The device as claimed in claim 20, wherein the predetermined parameters comprises the public key based on the first encryption method, global public elements based on the second encryption method and a public key based on the second encryption method.

23. The device as claimed in claim 20, wherein the first encryption method comprises a public key encryption method, and wherein the predetermined parameters are encrypted with the public key of the first node based on the first encryption method.

24. The device as claimed in claim 20, wherein the second encryption method comprises the Diffie-Hellman encryption method, and a common key is created by using the public key of the first node created by the Diffie-Hellman encryption method through the decrypted ciphertext, and a private key of the first node based on the Diffie-Hellman encryption method.