Secure communication using non-systematic error control codes

• US 8,667,380 B2
• Filed: 10/08/2009
• Issued: 03/04/2014
• Est. Priority Date: 10/09/2008
• Status: Expired due to Fees

• Current Assignee: Korea Advanced Institute of Science and Technology, Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Korea Advanced Institute of Science and Technology, Georgia Tech Research Corporation (University System of Georgia)
• Inventors: McLaughlin, Steven William, Klinc, Demijan, Ha, Jeongseok
• Primary Examiner(s): Chung, Phung M
• Application Number:
  US13/123,669
• Publication Number:
  US 20110246854A1
• Time in Patent Office: 1,608 Days
• Field of Search: 714/746, 714/752, 714/704, 714/790, 714/755, 714/801, 714/758, 380/270, 380/255
• US Class Current: 714/790
• CPC Class Codes: H03M 13/01 Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload

Abstract

A transmitter device (110T) for secure communication includes: an encoder (170) configured to apply a non-systematic error correcting code (NS ECC) to a message, thus producing encoded bits with no clear message bits; and a transceiver (720) configured to transmit the encoded bits over a main channel to a receiver. A method for secure communication includes: encoding a message with an NS ECC to produce an encoded message carrying no message bits in the clear; and transmitting the encoded message over a main channel (120). The NS ECC characteristics result in an eavesdropper channel error probability under a security threshold (320) and a main channel error probability over a reliability threshold (310), whenever an eavesdropper (140) listening on an eavesdropper channel (150) is more than distance Z (220) from the transmitter. Unreliable bits in the encoded bits render the eavesdropper unable to reliably decode messages on the main channel.

Claims

1. A method for secure communication in a system involving a transmitter device, a receiver device, and an eavesdropper device, the transmitter device being configured to transmit to the receiver device on a main channel, the eavesdropper device being configured to listen on an eavesdropper channel to the transmitter device, the main channel having a first signal-to-noise ratio, the eavesdropper channel having a second signal-to-noise ratio, the method implemented in the transmitter device and comprising:

encoding a message with a non-systematic error correcting code (NS ECC) to produce an encoded message without the message being carried in the clear; and

transmitting the encoded message to the receiver device using the main channel;

wherein the NS ECC has a defined characteristic such that when the eavesdropper device is more than a predetermined distance from the transmitter device, at least a portion of the message is unable to be recovered by the eavesdropper device decoding the encoded message.

2. The method of claim 1, wherein the message is encoded at a physical layer.

3. The method of claim 1, wherein the main channel comprises a wireless channel.

4. The method of claim 1, wherein the NS ECC comprises a low density parity check code.

5. A transmitter device for secure communication in a system involving the transmitter device, a receiver device, and an eavesdropper device, the transmitter device being configured to transmit to the receiver device on a main channel, the eavesdropper device being configured to listen on an eavesdropper channel to the transmitter device, the main channel having a first signal-to-noise ratio, the eavesdropper channel having a second signal-to-noise ratio, the transmitter device comprising:

an encoder configured to apply a non-systematic error correcting code (NS ECC) to a message to produce a plurality of encoded bits, wherein the plurality of encoded bits results in the message not being carried in the clear; and

a transceiver configured to transmit the plurality of encoded bits to the receiver device using the main channel;

wherein the NS ECC has a defined characteristic such that when the eavesdropper device is more than a predetermined distance from the transmitter device, a bit error probability on the eavesdropper channel does not exceed a predetermined security threshold while a bit error probability on the main channel exceeds a predetermined reliability threshold; and

wherein a subset of the plurality of encoded bits render the eavesdropper device unable to accurately decode the message.

6. A system for secure communication, the system comprising:

a receiver device; and

a transmitter device in communication with the receiver device using a main channel, the transmitter device configured to communicate a message without transmitting any of the message in the clear by applying a non-systematic error correcting code (NS ECC) and transmitting a portion of a plurality of encoded bits for the message;

wherein the receiver device is configured to recover the message from the plurality of encoded bits that were transmitted; and

wherein the NS ECC has a defined characteristic such that when an eavesdropper device listening on an eavesdropper channel to the transmitter device is more than a predetermined distance from the transmitter, a bit error probability for the eavesdropper channel does not exceed a predetermined security threshold while a bit error probability for the main channel exceeds a predetermined reliability threshold; and

wherein the plurality of encoded bits includes a plurality of bits that render the eavesdropper unable to accurately decode the message.

7. The system of claim 6, wherein the main channel comprises a wireless channel.

8. The system of claim 6, wherein the transmitter device is a radio frequency identification (RFID) tag.

9. A transmitter device for secure communication in a system involving the transmitter device, a receiver device, and an eavesdropper device, the transmitter device configured to transmit to the receiver device on a main channel, the eavesdropper device configured to listen on an eavesdropper channel to the transmitter device, the main channel having a first signal-to-noise ratio, the eavesdropper channel having a second signal-to-noise ratio, the transmitter device comprising:

a physical layer component of a protocol stack, the physical layer component configured to receive a message from another component of the protocol stack, the physical layer component comprising an encoder configured to apply a non-systematic error correcting code (NS ECC) to the message to produce a plurality of encoded bits, the plurality of encoded bits being produced such that the message is not carried in the clear; and

an RF transceiver configured to transmit the plurality of encoded bits to the receiver device using the main channel.

10. An encoder residing in a transmitter device, the encoder providing secure communication in a system involving the transmitter device, a receiver device, and an eavesdropper device, the transmitter device being configured to transmit to the receiver device on a main channel, the eavesdropper device being configured to listen on an eavesdropper channel to the transmitter device, the main channel having a first signal-to-noise ratio, the eavesdropper channel having a second signal-to-noise ratio, the encoder comprising:

coding logic configured to apply a non-systematic error correcting code (NS ECC) to a message to produce a plurality of encoded bits such that the message is not carried in the clear; and

puncture logic configured to puncture at least a portion of the plurality of encoded bits and to provide the at least a portion of the plurality of encoded bits that were punctured for transmission over the main channel;

wherein the NS ECC has a defined characteristic such that when the eavesdropper device is more than a predetermined distance from the transmitter device, a bit error probability on the eavesdropper channel does not exceed a predetermined security threshold while a bit error probability on the main channel exceeds a predetermined reliability threshold; and

wherein a subset of the plurality of encoded bits render the eavesdropper unable to accurately decode the message.

11. The encoder of claim 10, wherein the NS ECC comprises a low density parity check code.

12. The encoder of claim 10, wherein the puncture logic is configured to puncture all of the plurality of encoded bits.