Generation of Perfectly Secret Keys in Wireless Communication Networks

• US 20120281834A1
• Filed: 07/12/2012
• Published: 11/08/2012
• Est. Priority Date: 01/27/2005
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Reznik, Alexander, Kumoluyi, Akinlolu Oloruntosi, Zhang, Guodong, Chitrapu, Prabhakar R., Sternberg, Gregory S., Shah, Yogendra C., Briancon, Alain Charles Louis, Ye, Chunxuan
• Granted Patent: US 9,130,693 B2
• Time in Patent Office: Days
• US Class Current: 380/270
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 9/0858 Details about key distillation or coding, e.g. reconciliation, error correction, privacy amplification, polarisation coding or phase coding
• CPC Class Codes: H04L 9/0875 based on channel impulse response [CIR]
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 12/0431 Key distribution or pre-distribution; Key agreement
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A method and apparatus is used for generating a perfectly random secret key between two or more transceivers in a wireless communication network. In a point-to-point system, both transceivers produce an estimate of the channel impulse response (CIR) based on the received radio signal. The CIR estimation is synchronized and may include error correction and detection. A long secret key of bits is generated from a digitized version of the CIR estimate, from which a perfectly secret encryption key is derived by privacy amplification.

Claims

1. A method comprising:

receiving a radio signal at a first wireless transmit/receive unit (WTRU);

generating a channel impulse response (CIR) estimate at the first WTRU for the radio signal;

determining a starting point within the CIR estimate at the first WTRU;

transmitting the starting point from the first WTRU to a second WTRU;

generating a long secret key based on the CIR estimate at the first WTRU; and

generating a perfectly secret encryption key based on the long secret key at the first WTRU.

2. The method of claim 1, wherein the radio signal is received from the second WTRU.

3. The method of claim 1, further comprising:

selecting a block code;

generating block code parity bits; and

transmitting the block code parity bits to the second WTRU.

4. The method of claim 3, wherein the block code is selected based on a channel condition.

5. The method of claim 1, further comprising receiving antenna configuration information from the second WTRU, wherein generating the CIR estimate comprising generating the CIR estimate based, at least in part, on the antenna configuration information.

6. A wireless transmit/receive unit (WTRU) comprising:

a receiver configured to receive a radio signal;

a processor configured to;

generate a channel impulse response (CIR) estimate for the radio signal;

determine a starting point within the CIR estimate;

generate a long secret key based on the CIR estimate; and

generate a perfectly secret encryption key based on the long secret key; and

a transmitter configured to transmit the starting point to a second WTRU.

7. The WTRU of claim 6, wherein the radio signal is received from the second WTRU.

8. The WTRU of claim 6, wherein the processor is further configured to select a block code and generate block code parity bits;

and wherein the transmitter is further configured to transmit the block code parity bits to the second WTRU.

9. The WTRU of claim 8, wherein the block code is selected based on a channel condition.

10. The WTRU of claim 6, wherein the receiver is further configured to receive antenna configuration information from the second WTRU;

and

wherein the processor configured to generate the CIR estimate comprises the processor configured to generate the CIR estimate based, at least in part, on the antenna configuration information.

11. A method comprising:

receiving a radio signal at a first wireless transmit/receive unit (WTRU);

receiving a starting point for CIR estimation from a second WTRU at the first WTRU;

generating, at the first WTRU, a channel impulse response (CIR) estimate for the radio signal using the starting point;

generating a long secret key based on the CIR estimate; and

generating a perfectly secret encryption key based on the long secret key.

12. The method of claim 11, wherein the radio signal is received from the second WTRU.

13. The method of claim 11, further comprising receiving block code parity bits from the second WTRU.

14. The method of claim 13, further comprising performing error correction on the CIR estimate using the block code parity bits.

15. The method of claim 11, further comprising receiving antenna configuration information from the second WTRU, wherein generating the CIR estimate comprising generating the CIR estimate based, at least in part, on the antenna configuration information.

16. A wireless transmit/receive unit (WTRU) comprising:

a receiver configured to;

receive a radio signal; and

receive a starting point for a CIR estimate from a second WTRU; and

a processor configured to;

generate a channel impulse response (CIR) estimate for the radio signal using the starting point;

generate a long secret key based on the CIR estimate; and

generate a perfectly secret encryption key based on the long secret key.

17. The WTRU of claim 16, wherein the radio signal is received from the second WTRU.

18. The WTRU of claim 16, wherein the receiver is further configured to receive block code parity bits from the second WTRU.

19. The WTRU of claim 18, wherein the processor is further configured to perform error correction on the CIR estimate using the block code parity bits.

20. The WTRU of claim 16, wherein the receiver is further configured to receive antenna configuration information from the second WTRU;

and

wherein the processor configured to generate the CIR estimate comprises the processor configured to generate the CIR estimate based, at least in part, on the antenna configuration information.