WIRELESS NETWORK SECURITY USING RANDOMNESS

• US 20090138715A1
• Filed: 11/24/2008
• Published: 05/28/2009
• Est. Priority Date: 11/24/2007
• Status: Active Grant

• Current Assignee: University Of Massachusetts
• Original Assignee: University Of Massachusetts
• Inventors: Gong, Weibo, Xiao, Sheng
• Granted Patent: US 8,204,224 B2
• Time in Patent Office: Days
• US Class Current: 713/171
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061

Abstract

The present invention provides systems and methods for securing communications in a wireless network by utilizing the inherent randomness of propagation errors to enable legitimate users to dynamically create a shared symmetric secret key. In one embodiment, the invention provides a system with two computers each having a wireless network adapter. The sending node encodes the frames, transmits the frames, determines if the frames were correctly received, retransmits the frames if they were not correctly received, stores the frames that were not retransmitted, and applies a uses the stored frames to generate a secret key. The receiving node receives the encoded frames, determines if the frames were retransmitted, stores at least one of the frames that was not retransmitted, and uses the stored frames to generate the same secret key as the receiving node.

Claims

1. A computer-implemented method for generating a secret key at a first physical computing device in a wireless network, comprising:

encoding one or more frames with dense parity check codes at the first physical computing device;

transmitting the frames to a second physical computing device;

determining if the frames were correctly received at the second physical computing device;

retransmitting the frames to the second physical computing device if the frames were not correctly received at the second physical computing device;

storing at least one of the frames that was not retransmitted at the first physical computing device; and

applying a hashing algorithm to the stored frames to generate a secret key at the first physical computing device.

2. The computer-implemented method of claim 1, where the dense parity check codes are detectable but not correctable equiprobable parity check codes.

3. A computer-implemented method for generating a secret key at a second physical computing device in a wireless network, comprising:

receiving one or more frames encoded with dense parity check codes from a first physical computing device;

determining if the frames were retransmitted by the first physical computing device;

storing at least one of the frames that was not retransmitted by the first physical computing device at the second physical computing device; and

applying a hashing algorithm to the stored frames to generate a secret key at the second physical computing device.

4. The computer-implemented method of claim 3, where the dense parity check codes are detectable but not correctable equiprobable parity check codes.

5. A computer-implemented method for generating a secret key at a first physical computing device in a wireless network, comprising:

encoding one or more frames with random string values and error correction codes;

transmitting the frames to a second physical computing device;

determining if the frames were correctly received at the second physical computing device;

retransmitting the frames to the second physical computing device if the frames were not correctly received at the second physical computing device;

storing at least one random string value from at least one of the frames that was not retransmitted at the first physical computing device; and

applying a primary amplification function to the stored string values to generate a secret key at the first physical computing device.

6. A computer-implemented method for generating a secret key at a second physical computing device in a wireless network, comprising:

receiving one or more frames encoded with random string values and error correction codes;

determining if the frames were retransmitted by the first physical computing device;

storing at least one random string value from at least one of the frames that was not retransmitted by the first physical computing device at the second physical computing device;

applying a primary amplification function to the stored string values to generate a secret key at the second physical computing device.

7. A system for generating a shared secret key at two or more physical computing devices in a wireless network, comprising:

a first physical computing device comprising a wireless network adapter, for encoding one or more frames, transmitting the frames, determining if the frames were correctly received, retransmitting the frames if the frames were not correctly received, storing at least one of the frames that was not retransmitted, and using the stored frames to generate a first secret key; and

a second physical computing device comprising a wireless network adapter, for receiving the one or more encoded frames from the first physical computing device, determining if the frames were retransmitted, storing at least one of the frames that was not retransmitted, and using the stored frames to generate a second secret key;

where the first secret key and the second secret key are the same.

8. The system of claim 7, where the first computing device encodes the one or more frames with dense parity check codes.

9. The system of claim 8, where the dense parity check codes are detectable but not correctable equiprobable parity check codes.

10. The system of claim 7, where a hashing algorithm is applied to the stored frames to generate a first secret key.

11. The system of claim 7, where a hashing algorithm is applied to the stored frames to generate a second secret key.

12. The system of claim 7, where the first computing device encodes the one or more frames with random string values and error correction codes.

13. The system of claim 7, where a primary amplification function is applied to the stored frames to generate a secret key at the first physical computing device.

14. The system of claim 13, where the primary amplification function is applied to the string values in the stored frames.

15. The system of claim 7, where a primary amplification function is applied to the stored frames to generate a secret key at the second physical computing device.

16. The system of claim 15, where the primary amplification function is applied to the string values in the stored frames.