Decentralized systems methods and computer program products for sending secure messages among a group of nodes

• US 6,363,154 B1
• Filed: 10/28/1998
• Issued: 03/26/2002
• Est. Priority Date: 10/28/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Peyravian, Mohammad, Zunic, Nevenko, Matyas, Stephen Michael Jr.
• Primary Examiner(s): Decady, Albert
• Assistant Examiner(s): Smithers, Matthew
• Application Number:
  US09/181,631
• Time in Patent Office: 1,245 Days
• Field of Search: 713/151, 713/171, 713/180, 380/44, 380/47, 380/273, 380/283, 380/284, 380/285, 705/71
• US Class Current: 380/283
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/065 for group communications cryptographic mechanisms or cryptographic arrangements for key management involving conference or group key H04L9/0833
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0827 involving distinctive intermediate devices or communication paths network architectures or network communication protocols using different networks H04L63/18
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds

Abstract

Secure messages are sent among a group of nodes selected from a plurality of nodes that are connected to a communications network, by defining a random secret key at a first one of the group of nodes. The random secret key is sent from the first one of the group nodes to remaining ones of the group of nodes. A random number is generated at a second one of the group of nodes. A one-way hash of the random number and the random secret key is performed at the second one of the group of nodes to generate a working key. A message is encrypted at the second one of the group of nodes, using the working key. The encrypted message and the random number is sent from the second one of the group of nodes to remaining ones of the group of nodes. The encrypted message and the random number are received at the remaining ones of the group of nodes. Each of the remaining ones of the group of nodes performs a one-way hash of the random number and the random secret key, to regenerate the working key. The message is then decrypted using the regenerated working key. The secret key may be defined at any one of the group of nodes rather than a predefined, centralized key distribution center. Moreover, the random number may be generated at any one of the group of nodes that desires to communicate an encrypted message to remaining ones of the group of nodes. Decentralized group key management is thereby provided.

Claims

1. A method of sending secure messages among a group of nodes selected from a plurality of nodes that are connected to a communications network, the method comprising the steps of:

defining a random secret key at a first one of the group of nodes;

sending the random secret key from the first one of the group of nodes to remaining ones of the group of nodes;

generating a random number at a second one of the group of nodes;

performing a one way hash of the random number and the random secret key at the second one of the group of nodes to generate a working key;

encrypting a message at the second one of the group of nodes, using the working key; and

sending the encrypted message and the random number from the second one of the group of nodes to remaining ones of the group of nodes.

2. A method according to claim 1 further comprising the following steps that are performed at the remaining ones of the group of nodes:

performing a one way hash of the random number and the random secret key to regenerate the working key; and

decrypting the message using the regenerated working key.

3. A method according to claim 1 wherein the following steps are performed at the second one of the group of nodes, between the steps of performing a one way hash and encrypting a message:

generating a data encrypting key; and

encrypting the data encrypting key with the working key;

wherein the step of encrypting a message comprises the step of encrypting a message at the second one of the group of nodes, using the encrypted data encrypting key; and

wherein the step of sending the encrypted message comprises the step of sending the encrypted message, the random number and the encrypted data encrypting key from the second one of the group of nodes to remaining ones of the group of nodes.

4. A method according to claim 3 further comprising the following steps that are performed at the remaining ones of the group of nodes:

performing a one way hash of the random number and the random secret key to regenerate the working key;

decrypting the encrypted data encrypting key using the regenerated working key; and

decrypting the message using the decrypted encrypted data encrypting key.

5. A method according to claim 1:

wherein the step of performing a one way hash comprises the step of performing a one way hash of the random number, the random secret key and control information at the second one of the group of nodes to generate a working key; and

wherein the step of sending comprises the step of sending the encrypted message, the random number and the control information from the second one of the group of nodes to remaining ones of the group of nodes.

6. A method according to claim 1 wherein the following step is performed prior to the step of sending:

generating a signature by encrypting a one way hash of the random number with a private key of the second one of the group of nodes; and

wherein the step of sending comprises the step of sending the encrypted message, the random number and the signature from the second one of the group of nodes to remaining ones of the group of nodes.

7. A method according to claim 5 wherein the control information is at least one of an identification of the group of nodes, an identification of the second one of the group of nodes and an identification of permitted uses of the working key.

8. A group of nodes selected from a plurality of nodes that are connected to a communications network, the group of nodes sending secure messages to one another, each node in the group of nodes comprising:

means for defining a random secret key;

means for sending the random secret key to the group of nodes;

means for generating a random number;

means for performing a one way hash of the random number and the random secret key to generate a working key;

means for encrypting a message using the working key; and

means for sending the encrypted message and the random number to the group of nodes.

9. A group of nodes according to claim 8, wherein each node further comprises:

means for decrypting the message using the regenerated working key.

10. A group of nodes according to claim 8, wherein each node further comprises:

means for generating a data encrypting key; and

means for encrypting the data encrypting key with the working key;

wherein the means for encrypting a message comprises means for encrypting a message using the data encrypting key; and

wherein the means for sending the encrypted message comprises means for sending the encrypted message, the random number and the encrypted data encrypting key to the group of nodes.

11. A group of nodes according to claim 10, wherein each node further comprises:

means for decrypting the encrypted data encrypting key using the regenerated working key; and

means for decrypting the message using the decrypted data encrypting key.

12. A group of nodes according to claim 8:

wherein the means for performing a one way hash comprises means for performing a one way hash of the random number, the random secret key and control information at the second one of the group of nodes to generate a working key; and

wherein the means for sending comprises means for sending the encrypted message, the random number and the control information to the group of nodes.

13. A group of nodes according to claim 8, wherein each node further comprises:

means for generating a signature by encrypting a one way hash of the random number with a private key of the node; and

wherein the means for sending comprises means for sending the encrypted message, the random number and the signature to the group of nodes.

14. A group of nodes according to claim 12 wherein the control information is at least one of an identification of the group of nodes, an identification of the node and an identification of permitted uses of the working key.

15. A computer program product that sends secure messages to a group of nodes selected from a plurality of nodes that are connected to a communications network, the computer program product comprising a computer-readable storage medium having computer-readable program code means embodied in the medium, the computer-readable program code means comprising:

computer-readable program code means for defining a random secret key;

computer-readable program code means for sending the random secret key to the group of nodes,

computer-readable program code means for generating a random number;

computer-readable program code means for performing a one way hash of the random number and the random secret key to generate a working key;

computer-readable program code means for encrypting a message using the working key; and

computer-readable program code means for sending the encrypted message and the random number to the group of nodes.

16. A computer program product according to claim 15 further comprising:

computer-readable program code means for decrypting the message using the regenerated working key.

17. A computer program product according to claim 15 further comprising:

computer-readable program code means for generating a data encrypting key; and

computer-readable program code means for encrypting the data encrypting key with the working key;

wherein the computer-readable program code means for encrypting a message comprises computer-readable program code means for encrypting a message using the encrypted data encrypting key; and

wherein the computer-readable program code means for sending the encrypted message comprises computer-readable program code means for sending the encrypted message, the random number and the encrypted data encrypting key to the group of nodes.

18. A computer program product according to claim, 17 further comprising:

computer-readable program code means for decrypting the encrypted data encrypting key using the regenerated working key; and

computer-readable program code means for decrypting the message using the decrypted encrypted data encrypting key.

19. A computer program product according to claim 15:

wherein the computer-readable program code means for performing a one way hash comprises computer-readable program code means for performing a one way hash of the random number, the random secret key and control information at the second one of the group of nodes to generate a working key; and

wherein the computer-readable program code means for sending comprises computer-readable program code means for sending the encrypted message, the random number and the control information to the group of nodes.

20. A computer program product according to claim 15 further comprising:

computer-readable program code means for generating a signature by encrypting a one way hash of the random number with a private key of the node; and

wherein the computer-readable program code means for sending comprises computer-readable program code means for sending the encrypted message, the random number and the signature to the group of nodes.

21. A computer program product according to claim 19 wherein the control information is at least one of an identification of the group of nodes, an identification of the node and an identification of permitted uses of the working key.