Camouflage of network traffic to resist attack

• US 7,171,493 B2
• Filed: 12/19/2001
• Issued: 01/30/2007
• Est. Priority Date: 12/19/2001
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Shu, Li, Weinstein, William
• Primary Examiner(s): VU, THONG H
• Application Number:
  US10/025,017
• Publication Number:
  US 20030115364A1
• Time in Patent Office: 1,868 Days
• Field of Search: 709/246, 709/232, 709/206, 709/250, 709/201, 709/225, 709/228, 709/238, 709/230, 709/234, 709/208, 709/221, 370/230, 370/389, 370/400, 370/352, 370/350, 370/238, 370/392, 370/395, 455/432, 713/200, 713/201, 714/749
• US Class Current: 709/246
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• 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 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 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it
• CPC Class Codes: H04L 63/1458 Denial of Service
• CPC Class Codes: H04L 63/1466 Active attacks involving interception, injection, modification, spoofing of data unit addresses, e.g. hijacking, packet injection or TCP sequence number attacks
• 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

An apparatus for transmitting a file with enhanced transmission security through a network includes a file-splitting processor that splits the file into a plurality of message segments and addresses the plurality of message segments to a plurality of addresses assigned to a receiving host. The apparatus includes a message segment transmitter for transmitting the plurality of message segments to the receiving host.

Claims

1. An apparatus for transmitting a file through a network, the apparatus comprising:

a file-splitting processor for splitting a file into a plurality of message segments and assigning one of a plurality of final different destination addresses to each segment, each of the plurality of final different destination addresses being assigned to a single receiving host; and

a message segment transmitter for transmitting the plurality of message segments to the receiving host using the plurality of final different destination addresses.

2. The apparatus of claim 1 wherein the file-splitting processor further comprises a file converter for converting the file into N message segments such that the file is reassemblable from a subset of any K of the message segments at the receiving host, N and K being positive integers and N>

K>

1.

3. The apparatus of claim 1 wherein the file-splitting processor is configured for assigning one of a plurality of initial source addresses to each of the plurality of message segments, thereby impeding attempts to ascertain the source of the file.

4. The apparatus of claim 1, further comprising a message segment monitor for detecting non-receipt of a subset of the plurality of message segments.

5. The apparatus of claim 1, further comprising an address allocator for assigning a subset of the plurality of destination addresses to the receiving host.

6. An apparatus for transmitting a file through a network, the apparatus comprising:

a file-splitting processor for splitting the file into a plurality of message segments and assigning one of a plurality of different initial source addresses to each message segment of the plurality of message segments, each initial source address being assigned to a single source host, thereby disguising the origin of the file; and

a message segment transmitter for transmitting the plurality of message segments to a receiving host.

7. The apparatus of claim 6 wherein the file-splitting processor is configured for assigning one of the plurality of different final destination addresses assigned to the receiving host to each message segment of the plurality of message segments.

8. A method for securely transmitting a file through a network, the method comprising:

(a) at a source host, splitting the file into a plurality of message segments;

(b) addressing, at the source host, each message segment of the plurality of message segments using one of a plurality of different final destination addresses, each of the different final destination addresses being assigned to a single receiving host; and

(c) transmitting the plurality of message segments to the receiving host with the plurality of different final destination addresses.

9. The method of claim 8 wherein the plurality of message segments are addressed in one-to-one correspondence to at least a subset of the plurality of different destination addresses.

10. The method claim 8 wherein splitting the file into a plurality of message segments comprises converting the file into N message segments such that the file is reassemblable from a subset of any K of the message segments, N and K being positive integers and N>

K>

1.

11. The method of claim 10, further comprising assigning N different final destination addresses to the receiving host, wherein the N message segments are addressed using one of the N final different destination addresses assigned to the receiving host.

12. The method of claim 11, further comprising causing the receiving host to cease receiving messages on at least one of the N different final destination addresses in response to an attack on the at least one of the final destination addresses.

13. The method of claim 12 wherein the receiving host ceases to receive messages via no more than (N−

K) different final destination addresses, thereby facilitating reassembly of the file by the host.

14. The method of claim 11, further comprising:

(e) reassembling the N message segments into a reassembled file at the receiving host;

(f) splitting the reassembled file into a second set of N message segments at the receiving host; and

(g) transmitting the second set of N message segments from the receiving host using the N different final destination addresses.

15. The method of claim 10, further comprising:

(d) periodically reassigning at least a subset of the plurality of different final destination addresses assigned to the receiving host while leaving at least K of the different final destination addresses unchanged thereby permitting continuous receipt of messages by the receiving host, and

(e) notifying at least a portion of the network of the reassigned different final destination addresses.

16. The method of claim 8, further comprising:

(d) retransmitting the plurality of message segments from the receiving host.

17. The method of claim 16, wherein retransmitting the plurality of message segments from the receiving host comprises retransmitting the plurality of message segments to at least two of a plurality of intermediate hosts, thereby relaying the plurality of message segments along more than one path through the network.

18. The method of claim 8, further comprising:

(d) selecting a virtual network comprising a plurality of hosts, the plurality of hosts including the receiving host;

(e) assigning each host of the plurality of hosts to a domain of a plurality of domains;

(f) designating sets of the host pairs, each host pair comprising two hosts assigned to the same domain or a neighboring domain; and

(g) constraining travel of each message segment of the plurality of message segments to the receiving host via relays between host pairs.

19. The method of claim 8, further comprising:

(d) assigning a source address selected from a plurality of initial source addresses to each message segment of the plurality of message segments, thereby impeding attempts to ascertain the source of the file.

20. The method of claim 8, further comprising:

(d) receiving, at the receiving host, at least a portion of the plurality of message segments;

(e) reassembling the file from the received message segments at the receiving host;

(f) splitting the reassembled file into a second plurality of message segments at the receiving host; and

(g) transmitting the second plurality of message segments from the receiving host.

21. The method of claim 8 wherein step (c) comprises transmitting the plurality of message segments to at least one of an intermediate host and a destination host.

22. The method of claim 8 wherein step (c) comprises transmitting from at least one of a source host and an intermediate host.

23. The method of claim 8, further comprising monitoring non-receipt by the receiving host of at least one of the plurality of message segments.

24. The method of claim 8, further comprising:

(d) allocating M different final destination addresses for assignment to the receiving host;

(e) assigning N final destination addresses of the M allocated final destination addresses, where N is less than or equal to M; and

(e) periodically reassigning to the receiving host at least a portion of the N final destination addresses.

25. The method of claim 8, further comprising:

(d) adding status information associated with a sending host to the message segment; and

(e) upon receipt by the receiving host, interpreting the status information to detect tampering with message segment transmission.

26. The method of claim 8, further comprising:

(d) encoding the file to produce an encoded bit file having encoded bits, and

(e) scrambling the encoded bits, such that the encoded bit file is split into a plurality of message segments.

27. A method of securely transmitting a file through a network, the method comprising:

(a) splitting the file into a plurality of message segments at a source host;

(b) at the source host, assigning one initial source address of a plurality of different initial source addresses to each message segment of the plurality of message segments, each of the different initial source addresses being assigned to the source host, thereby disguising the origin of the file; and

(c) transmitting the plurality of message segments.

28. The method of claim 27, further comprising:

(d) assigning one final destination address of a plurality of final destination addresses assigned to a receiving host to each message segment of the plurality of message segments.

29. A method for securely transmitting a file through a network, the method comprising:

(a) splitting the file into a plurality of message segments, each message segment comprising;

(i) one of a plurality of different final destination specifiers, each of the final destination specifiers being attributed to a single final destination host;

(ii) encrypted protocol information; and

(iii) encrypted message data;

(b) receiving a message segment at a receiving host;

(c) decrypting the message data to determine the final destination host;

(d) encrypting the message data in accordance with an encryption protocol accessible to the final destination host;

(e) transmitting the encrypted message segment to the final destination host; and

(f) repeating steps (a)–

(e) for other message segments, thereby facilitating recovery of the message by the final destination host.

30. The method of claim 29, wherein the message segment has a length, and further comprising altering the length.

31. The method of claim 29, wherein the receiving host and the final destination host negotiate to determine the encryption protocol.

32. The method of claim 29, further comprising causing the receiving host to adding status information concerning the receiving host to the message segment, and, at the receiving host, interpreting the status information to detect tampering with message segment transmission.