Method for establishing secure communication link between computers of virtual private network

• US 6,826,616 B2
• Filed: 11/07/2003
• Issued: 11/30/2004
• Est. Priority Date: 10/30/1998
• Status: Expired due to Term

• Current Assignee: VirnetX Inc. (Virnetx Holding Corporation)
• Original Assignee: Science Applications International Corporation
• Inventors: Larson, Victor, Short, III, Robert Dunham, Munger, Edmund Colby, Williamson, Michael
• Primary Examiner(s): Lim, Krisna
• Application Number:
  US10/702,580
• Publication Number:
  US 20040103205A1
• Time in Patent Office: 389 Days
• Field of Search: 709/227, 709/228, 370/351, 370/389, 713/201
• US Class Current: 709/228
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 61/45 Network directories; Name-to-address mapping
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/5076 Update or notification mechanisms, e.g. DynDNS
• CPC Class Codes: H04L 61/5092 by self-assignment, e.g. picking addresses at random and testing if they are already in use
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/0272 Virtual private networks
• CPC Class Codes: H04L 63/0281 Proxies
• CPC Class Codes: H04L 63/029 Firewall traversal, e.g. tunnelling or, creating pinholes
• CPC Class Codes: H04L 63/0414 during transmission, i.e. party's identity is protected against eavesdropping, e.g. by using temporary identifiers, but is known to the other party or parties involved in the communication
• CPC Class Codes: H04L 63/0421 Anonymous communication, i.e. the party's identifiers are hidden from the other party or parties, e.g. using an anonymizer
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/0876 based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/1458 Denial of Service
• CPC Class Codes: H04L 63/1491 : using deception as countermeasure, e.g. honeypots, honeynets, decoys or entrapment
• CPC Class Codes: H04L 63/18 : using different networks or channels, e.g. using out of band channels cryptographic mechanisms or cryptographic arrangements for key distribution involving distinctive intermediate devices or communication paths H04L9/0827; cryptographic mechanisms or cryptographic arrangements for authentication using a plurality of channels H04L9/3215

Abstract

A technique is disclosed for establishing a secure communication link between a first computer and a second computer over a computer network. Initially, a secure communication mode of communication is enabled at a first computer without a user entering any cryptographic information for establishing the secure communication mode of communication. Then, a secure communication link is established between the first computer and a second computer over a computer network based on the enabled secure communication mode of communication. The secure communication link is a virtual private network communication link over the computer network in which one or more data values that vary according to a pseudo-random sequence are inserted into each data packet.

Claims

1. A method for communicating using a private communication link between a client computer and a server computer over a computer network, the method comprising steps of:

sending an information packet from the client computer to the server computer over the computer network, the information packet containing data that is used for forming a virtual private connection between the client computer and the server computer, the data that is used for forming the virtual private connection being inserted into a payload portion of the information packet at the client computer by an application layer program;

receiving the information packet at a kernel layer of an operating system on the server computer; and

determining at the kernel layer of the operating system on the server computer whether the information packet contains the data that is used for forming the virtual private connection.

2. The method according to claim 1, further comprising a step of passing the information packet through a firewall before sending the information packet over the computer network.

3. The method according to claim 1, wherein the data used for forming the virtual private connection corresponds to a predetermined level of service provided to the client computer by the server computer.

4. The method according to claim 1, further comprising step of sending a second information packet from the server computer to the client computer over the computer network, the second information packet containing data that is used for forming the virtual private connection, the data that is used for forming the virtual private connection being inserted into a payload portion of the second information packet by the kernel layer of the operating system on the server computer.

5. The method according to claim 1, wherein the information packet is a UDP protocol information packet.

6. The method according to claim 1, wherein the information packet is one of a TCP/IP protocol information packet and an ICMP protocol information packet.

7. The method according to claim 1, wherein the data that is used for forming the virtual private connection includes one or more data values that vary according to a pseudo-random sequence.

8. The method according to claim 1, wherein the data that is used for forming the virtual private connection is based on a computer network address hopping regime that is used to pseudorandomly change computer network addresses in packets transmitted between the client computer and the server computer.

9. The method according to claim 1, wherein the data that is used for forming the virtual private connection is based on comparing a value in each data packet transmitted between the client computer and the server computer to a moving window of valid values.

10. The method according to claim 1, wherein the data that is used for forming the virtual private connection is based on a comparison of a discriminator field in a header of each data packet to a table of valid discriminator fields maintained for the client computer.

11. The method according to claim 1, wherein the computer network includes the Internet.

12. A computer-readable storage medium, comprising:

a storage area; and

computer-readable instructions for a method for communicating using a private communication link between a client computer and a server computer over a computer network, the method comprising steps of;

sending an information packet from the client computer to the server computer over the computer network, the information packet containing data that is used for forming a virtual private connection between the client computer and the server computer, the data that is used for forming the virtual private connection being inserted into a payload portion of the information packet at the client computer by an application layer program;

receiving the information packet at a kernel layer of an operating system on the server computer; and

determining at the kernel layer of the operating system on the server computer whether the information packet contains the data that is used for forming the virtual private connection.

13. The computer-readable medium according to claim 12, further comprising a step of passing the information packet through a firewall before sending the information packet over the computer network.

14. The computer-readable medium according to claim 12, wherein the data used for forming the virtual private connection corresponds to a predetermined level of service provided to the client computer by the server computer.

15. The computer-readable medium according to claim 12, further comprising step of sending a second information packet from the server computer to the client computer over the computer network, the second information packet containing data that is used for forming the virtual private connection, the data that is used for forming the virtual private connection being inserted into a payload portion of the second information packet by the kernel layer of the operating system on the server computer.

16. The computer-readable medium according to claim 12, wherein the information packet is a UDP protocol information packet.

17. The computer-readable medium according to claim 12, wherein the information packet is one of a TCP/IP protocol information packet and an ICMP protocol information packet.

18. The computer-readable medium according to claim 12, wherein the data that is used for forming the virtual private connection includes one or more data values that vary according to a pseudo-random sequence.

19. The computer-readable according to claim 12, wherein the data that is used for forming the virtual private connection is based on a computer network address hopping regime that is used to pseudorandomly change computer network addresses in packets transmitted between the client computer and the server computer.

20. The computer-readable medium according to claim 12, wherein the data that is used for forming the virtual private connection is based on comparing a value in each data packet transmitted between the client computer and the server computer to a moving window of valid values.

21. The computer-readable medium according to claim 12, wherein the data that is used for forming the virtual private connection is based on a comparison of a discriminator field in a header of each data packet to a table of valid discriminator fields maintained for the client computer.

22. The computer-readable medium according to claim 12, wherein the computer network includes the Internet.

23. A method for communicating using a private communication link between a client computer and a server computer over a computer network, the method comprising steps of:

generating an information packet at the client computer,

modifying the information packet at an application layer within the client computer by inserting data into a payload portion of the information packet that is used for forming a virtual private connection between the client computer and the server computer; and

sending the modified information packet from the client computer to the server computer over the computer network.

24. The method according to claim 23, further comprising a step of passing the modified information packet through a firewall before sending the modified information packet over the computer network.

25. The method according to claim 23, wherein the data used for forming the virtual private connection corresponds to a predetermined level of service provided to the client computer by the server computer.

26. The method according to claim 23, further comprising steps of:

receiving an information packet at the application layer in the client computer that is sent from the server computer over the computer network; and

determining at the application layer of the client computer whether the information packet contains data that is used for forming the virtual private connection.

27. The method according to claim 23, wherein the modified information packet is a UDP protocol information packet.

28. The method according to claim 23, wherein the modified information packet is one of a TCP/IP protocol information packet and an ICMP protocol information packet.

29. The method according to claim 23, wherein the data that is used for forming the virtual private connection includes one or more data values that vary according to a pseudo-random sequence.

30. The method according to claim 23, wherein the data that is used for forming the virtual private connection is based on a computer network address hopping regime that is used to pseudorandomly change computer network addresses in information packets transmitted between the client computer and the server computer.

31. The method according to claim 23, wherein the data that is used for forming the virtual private connection is based on comparing a value in each information packet transmitted between the client computer and the server computer to a moving window of valid values.

32. The method according to claim 23, wherein the data that is used for forming the virtual private connection is based on a comparison of a discriminator field in a header of each information packet to a table of valid discriminator fields maintained for the client computer.

33. The method according to claim 23, wherein the computer network includes the Internet.

34. A computer-readable storage medium, comprising:

a storage area; and

computer-readable instructions for a method for communicating using a private communication link between a client computer and a server computer over a computer network, the method comprising steps of;

generating an information packet at the client computer,

modifying the information packet at an application layer within the client computer by inserting data into a payload portion of the information packet that is used for forming a virtual private connection between the client computer and the server computer; and

sending the modified information packet from the client computer to the server computer over the computer network.

35. The computer-readable medium according to claim 34, further comprising a step of passing the modified information packet through a firewall before sending the modified information packet over the computer network.

36. The computer-readable medium according to claim 34, wherein the data used for forming the virtual private connection corresponds to a predetermined level of service provided to the client computer by the server computer.

37. The computer-readable medium according to claim 34, further comprising steps of:

receiving an information packet at the application layer in the client computer that is sent from the server computer over the computer network; and

determining at the application layer of the client computer whether the information packet contains data that is used for forming the virtual private connection.

38. The computer-readable medium according to claim 34, wherein the modified information packet is a UDP protocol information packet.

39. The computer-readable medium according to claim 34, wherein the modified information packet is one of a TCP/IP protocol information packet and an ICMP protocol information packet.

40. The computer-readable medium according to claim 34, wherein the data that is used for forming the virtual private connection includes one or more data values that vary according to a pseudo-random sequence.

41. The computer-readable medium according to claim 34, wherein the data that is used for forming the virtual private connection is based on a computer network address hopping regime that is used to pseudorandomly change computer network addresses in information packets transmitted between the client computer and the server computer.

42. The computer-readable medium according to claim 34, wherein the data that is used for forming the virtual private connection is based on comparing a value in each information packet transmitted between the client computer and the server computer to a moving window of valid values.

43. The computer-readable medium according to claim 34, wherein the data that is used for forming the virtual private connection is based on a comparison of a discriminator field in a header of each information packet to a table of valid discriminator fields maintained for the client computer.

44. The computer-readable medium according to claim 34, wherein the computer network includes the Internet.

45. A method for communicating using a private communication link between a server computer and a client computer over a computer network, the method comprising steps of:

generating an information packet at the server computer,

modifying the information packet at a kernel layer within an operating system of the server computer by inserting data into a payload portion of the information packet that is used for forming a virtual private connection between the server computer and the client computer; and

sending the modified information packet from the server computer to an application layer in the client computer over the computer network.

46. The method according to claim 45, further comprising a step of passing the modified information packet through a firewall after the modified information packet is sent over the computer network before the modified information packet is received by the application layer at the client computer.

47. The method according to claim 45, wherein the data used for forming the virtual private connection corresponds to a predetermined level of service provided to the client computer by the server computer.

48. The method according to claim 45, wherein the modified information packet is a UDP protocol information packet.

49. The method according to claim 45, wherein the modified information packet is one of a TCP/IP protocol information packet and an ICMP protocol information packet.

50. The method according to claim 45, wherein the data that is used for forming the virtual private connection includes one or more data values that vary according to a pseudo-random sequence.

51. The method according to claim 45, wherein the data that is used for forming the virtual private connection is based on a computer network address hopping regime that is used to pseudorandomly change computer network addresses in modified information packets transmitted between the server computer and the client computer.

52. The method according to claim 45, wherein the data that is used for forming the virtual private connection is based on comparing a value in each data modified information packet transmitted between the server computer and the client computer to a moving window of valid values.

53. The method according to claim 45, wherein the data that is used for forming the virtual private connection is based on a comparison of a discriminator field in a header of each modified information packet to a table of valid discriminator fields maintained for the server computer.

54. The method according to claim 45, wherein the computer network includes the Internet.

55. A computer-readable storage medium, comprising:

a storage area; and

computer-readable instructions for a method for communicating using a private communication link between a server computer and a client computer over a computer network, the method comprising steps of;

generating an information packet at the server computer,

modifying the information packet at a kernel layer within an operating system of the server computer by inserting data into a payload portion of the information packet that is used for forming a virtual private connection between the server computer and the client computer; and

sending the modified information packet from the server computer to an application layer in the client computer over the computer network.

56. The computer-readable medium according to claim 55, further comprising a step of passing the modified information packet through a firewall after the modified information packet is sent over the computer network before the modified information packet is received by the application layer at the client computer.

57. The computer-readable medium according to claim 55, wherein the data used for forming the virtual private connection corresponds to a predetermined level of service provided to the client computer by the server computer.

58. The computer-readable medium according to claim 55, wherein the modified information packet is a UDP protocol information packet.

59. The computer-readable medium according to claim 55, wherein the modified information packet is one of a TCP/IP protocol information packet and an ICMP protocol information packet.

60. The computer-readable medium according to claim 55, wherein the data that is used for forming the virtual private connection includes one or more data values that vary according to a pseudo-random sequence.

61. The computer-readable medium according to claim 55, wherein the data that is used for forming the virtual private connection is based on a computer network address hopping regime that is used to pseudorandomly change computer network addresses in modified information packets transmitted between the server computer and the client computer.

62. The computer-readable medium according to claim 55, wherein the data that is used for forming the virtual private connection is based on comparing a value in each data modified information packet transmitted between the server computer and the client computer to a moving window of valid values.

63. The computer-readable medium according to claim 55, wherein the data that is used for forming the virtual private connection is based on a comparison of a discriminator field in a header of each modified information packet to a table of valid discriminator fields maintained for the server computer.

64. The computer-readable medium according to claim 55, wherein the computer network includes the Internet.