Using trusted associations to establish trust in a computer network

• US 5,872,847 A
• Filed: 07/30/1996
• Issued: 02/16/1999
• Est. Priority Date: 07/30/1996
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: ITT Industries (ITT, Inc.)
• Inventors: Maiwald, Eric S., Snow, deceased, David Wayne, Boyle, John, Nickel, James O., Levin, Stephen E., Holden, James M., Wrench, Edwin H. Jr.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): White, Carmen D.
• Application Number:
  US08/688,522
• Time in Patent Office: 931 Days
• Field of Search: 380/23, 380/25, 380/49, 395/186, 395/187.01, 395/200.01, 395/200.02
• US Class Current: 713/151
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method is disclosed for establishing trusted communications with associations for communications between users on an Internet Protocol based computer network. The method entails the first user determining the Internet Protocol (IP) address of a second user on the computer network through the use of Address Resolution Protocol (ARP) and Reverse Address Resolution Protocol (RARP). The first user then determining the accessability of the second user on the computer network. The users exchange security related information needed to complete the establishment of a trusted association. The trusted association is maintained during all communications between the first user and the second user.

Claims

1. A method for sharing a user'"'"'s trusted information, as needed, with another user over an Internet Protocol (IP) based computer network, said method comprising the steps of:

determining the Internet Protocol (IP) address of a second user on the computer network;

determining the accessability of the second user on the computer network by sending an Internet Control message Protocol (ICMP) Echo Request to said second user carrying the first user'"'"'s security parameter and including a security level, digital certificate including a public key and signature of a first secure network interface unit (SNIU) associated with said first user, and receiving an Internet Control message Protocol (ICMP) Echo Reply from said second user in response to said ICMP Echo Request, said Reply including;

an association key encrypted using a key algorithm, said second user'"'"'s security level, and a digital certificate and signature corresponding to a second SNIU associated with said second user;

exchanging, between the first user and the second user through said first and second SNIUs, security related information needed to complete the establishment of a trusted association; and

,

maintaining the trusted association during all communications between the first user and the second user,

wherein each intermediate SNIU, in the communications path between the first SNIU and second SNIU, which receives the ICMP Echo reply originating from the second user, authenticates the ICMP echo reply, extracts a release key from the ICMP echo reply corresponding to the previous SNIU, generates a new release key corresponding to the next SNIU and encrypts the key using the public key corresponding to the next SNIU, removes the previous certificate and signature, appends its certificate, and digitally signs the ICMP Echo Reply before sending it on to the next SNIU.

2. The method according to claim 1, wherein the step of determining the Internet Protocol (IP) address of the second user utilizes Address Resolution Protocol (ARP).

3. The method according to claim 1, wherein the step of determining the Internet Protocol (IP) address of the second user utilizes Reverse Address Resolution Protocol (RARP).

4. The method according to claim 1, wherein the step of exchanging security related information to establish trust occurs at the session layer in the communication stack.

5. The method according to claim 1, wherein each intermediate SNIU, in the communications path between the first user and the second user, which receives the Internet Control Message Protocol (ICMP) Echo Request, authenticates the Internet Control Message Protocol (ICMP) Echo Request, saves a copy of the first user'"'"'s certificate, appends its certificate to the Internet Control Message Protocol Echo Request, and digitally signs the Internet Control Message Protocol Echo Request before sending it on to the second SNIU.

6. The method according to claim 1, wherein each intermediate SNIU, prior to relaying the ICMP Echo reply to the next SNIU, determines if transmitting the information from the second user to the first user would violate a security policy.

7. A method for sharing a user'"'"'s trusted information, as needed, with another user over an Internet Protocol (IP) based computer network via secure nework interface units (SNIUs) to communicate data information in the form of datagrams, said method comprising the steps of:

receiving an IP datagram at a first SNIU from a first user host destined for a second user host;

placing said IP datagram in a wait queue;

determining the Internet Protocol (IP) address of a second SNIU associated with the second user host on the computer network;

determining the accessability of the second user host on the computer network, including the steps of;

sending an Internet Control message Protocol (ICMP)

Echo Request to said second user host carrying the first user host security level and a digital certificate including a public key, and signature corresponding to said first SNIU;

sending an Internet Control message Protocol (ICMP) Echo Reply from said second user host to said first SNIU in response to said ICMP Echo Request, said Reply including;

an association key encrypted using a key exchange algorithm,

said second user host security level, and a digital certificate and signature of a second SNIU, said second SNIU associated with said second user host;

receiving and authenticating the ICMP Echo Reply at the first SNIU to establish a trusted association between the first and second user hosts; and

removing said IP datagram from the wait queue and encrypting the datagram using the association key for transfer to said second user host during the trusted association.

8. The method according to claim 7, wherein each intermediate SNIU, in the communications path between the first SNIU and the second SNIU, which receives the ICMP Echo Request, authenticates the ICMP Echo Request, saves a copy of the previous SNIU'"'"'s certificate, appends its certificate to the Internet Control Message Protocol Echo Request, and digitally signs the Internet Control Message Protocol Echo Request before sending it on to the next SNIU.

9. The method according to claim 8, wherein each intermediate SNIU, in the communications path between the first SNIU and the second SNIU, which receives the ICMP Echo reply from the second user host, authenticates the ICMP echo reply, extracts a release key from the ICMP echo reply corresponding to the previous SNIU, generates a new release key corresponding to the next SNIU and encrypts the key using the public key corresponding to the next SNIU, removes the previous certificate and signature corresponding to a previous intermediate SNIU, appends its certificate, and digitally signs the ICMP Echo Reply before sending it on to the next SNIU.