Method and apparatus for enhancing security of wireless communications

• US 7,904,723 B2
• Filed: 07/29/2005
• Issued: 03/08/2011
• Est. Priority Date: 01/12/2005
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zhang, Guodong, Shin, Sung-Hyuk, Reznik, Alexander, Chitrapu, Prabhakar R.
• Primary Examiner(s): Arani; Taghi T
• Assistant Examiner(s): Rahman; Mahfuzur
• Application Number:
  US11/192,918
• Publication Number:
  US 20060156009A1
• Time in Patent Office: 2,048 Days
• Field of Search: 713/176
• US Class Current: 713/176
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0838 using one-time-passwords
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 63/16 Implementing security features at a particular protocol layer
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/10 Integrity

Abstract

The present invention is related to a method and apparatus for enhancing security of communications. The apparatus comprises a security processing unit, a data processing unit, a cross-layer watermarking unit, and optionally a smart antenna processor. The security processing unit generates a token/key to be used in watermarking and sends a node security policy to other components. The data processing unit generates user data. The cross-layer watermarking unit includes at least one of Layer-2/3, Layer-1 and Layer-0. Each layer performs a different scheme or degree of watermarking. The cross-layer watermarking unit embeds the token/key into the user data transmission on at least one of the layers selectively in accordance with a security policy.

Claims

1. A method for enhancing security of a communication transmitted by a communicating device, the method comprising:

providing a cross-layer watermarking unit in the communicating device, that communicates a token or a key as a watermark message, the cross-layer watermarking unit comprising at least one of an RF watermarking layer, a physical watermarking layer, and a higher watermarking layer;

generating a token or a key for encoding watermarking user data;

examining the user data in preparation for embedding;

embedding each token or key on a bit level into the user data by the cross layer watermarking unit using dirty paper coding (DPC) as a function of the user data stream;

sending a node security policy to the cross-layer watermarking unit, wherein the security policy includes selection of a radio interface (RI) independent token or key, a RI specific token or key, or both;

transmitting the user data at one or more communication layers for transport watermarking at a transport level in accordance with the node security policy; and

authenticating the user data with the token or key embedded into the user data transmission.

2. The method of claim 1 wherein the DPC is further utilized for broadcasting and multicasting the user data.

3. The method of claim 1 wherein embedding the token or key from the security processing unit into the user data is performed using a signature of the communication device.

4. The method of claim 3 wherein the signature is a hardware non-linearity of the communication device.

5. The method of claim 1 further comprising processing parameters received at a smart antenna processor for embedding the token or key into the user data transmission.

6. The method of claim 5 wherein the token or key represents information relating to the smart antenna.

7. The method of claim 6 wherein the information includes at least one of antenna patterns, antenna weights, delays between antenna elements, antenna spacing, antenna hardware information, antenna state, antenna configuration, antenna switching rate, antenna steering consistency, antenna cross correlation and characteristics of the spatial distribution.

8. The method of claim 5 wherein users are allocated between beams.

9. The method of claim 1 wherein the token or key is generated per connection.

10. The method of claim 1 wherein the token or key is generated per data packet.

11. The method of claim 1 wherein the token or key is placed in a least significant bit of the user data.

12. The method of claim 1 wherein the token or key is placed in a control field of the user data.

13. The method of claim 1 further comprising transmitting the user data in a layer higher than the higher watermarking layer for processing in accordance with a security policy.

14. The method of claim 1 wherein the token or key is one of a signature unique to an originator, a signature unique to a radio modem, and a low data rate stream.

15. The method of claim 1 wherein the watermarking is performed utilizing at least one of modulating carrier frequency within allowed limits, varying guard time intervals where the amount of the individual interval corresponds to a bit sequence of the watermark, introducing low level tones in the spectrum where each tone is associated with a watermark message, varying spectrum within allowed spectrum mask where a set of the filter coefficients is associated with a watermark message, using pseudo-randomly selected subcarriers in an orthogonal frequency division multiplex (OFDM) system where the selection is made according to watermarks being utilized.

16. The method of claim 1 wherein the watermarking is performed utilizing at least one of, a dirty paper coding (DPC) technique for watermark encoding, embedding the token/key into physical channel such that some of the redundancy bits of the channel code are replaced with bits relating to the token/key, transferring the token or key by initializing an forward error correction (FEC) shift register with the token or key prior to channel coding of the user data stream, changing the physical layer transmission format configuration where a set of the configuration corresponds to a watermark, modulating the amplitude in a constant envelope modulation scheme where the amount of the amplitude is an indication of bits of the watermark.

17. The method of claim 1 wherein the communication is transmitted in an orthogonal frequency division multiplexing (OFDM) system.

18. The method of claim 17 wherein the watermarking is performed by manipulating pilot sub carriers.

19. The method of claim 17 wherein the watermarking is performed by modifying transmitted carrier frequency in a predetermined pattern.

20. The method of claim 1 wherein the communication is transmitted in a code division multiple access system.

21. The method of claim 20 wherein the watermarking is performed by stealing spreading code chips in a predetermined pattern.

22. The method of claim 20 wherein the watermarking is performed by applying spreading code jitter with respect to the carrier frequency and frequency shift keying (FSK) modulation of watermark information on top of the jitter by placing a low frequency drift on the carrier frequency.

23. An apparatus for enhancing security of a communication, the apparatus comprising:

a security processing unit configured to generate a token or a key for encoding watermarking and to send a node security policy for processing data, wherein the security policy includes selection of a radio interface (RI) independent token or key, a RI specific token or key, or both;

a data processing unit comprising a processor configured to generate user data;

a cross-layer watermarking unit that communicates a token or a key as a watermark message, the cross-layer watermarking unit configured to process user data in least one of an RF watermarking layer, a physical watermarking layer, and a higher watermarking layer, whereby the cross-layer watermarking unit selectively embeds the token or key on a bit level into the user data transmission using dirty paper coding (DPC) as a function of the user data stream for transport watermarking at a transport level in accordance with a security policy, thereby authenticating the user data, the cross-layer watermarking unit having examined the user data in preparation for the embedding; and

a transmitter configured to transmit the user data at one or more communication layers for transport watermarking at a transport level in accordance with the node security policy.

24. The apparatus of claim 23 wherein DPC is further utilized for broadcasting and multicasting the user data.

25. The apparatus of claim 23 wherein embedding the token or key is performed using a signature of the communication device.

26. The apparatus of claim 25 wherein the signature is a hardware non-linearity of the communication device.

27. The apparatus of claim 23 further comprising a smart antenna processor for embedding the token or key into the user data transmission.

28. The apparatus of claim 27 wherein the token or key represents information relating to the smart antenna.

29. The apparatus of claim 28 wherein the information includes at least one of antenna patterns, antenna weights, delays between antenna elements, antenna spacing, antenna hardware information, antenna state, antenna configuration, antenna switching rate, antenna steering consistency, antenna cross correlation and characteristics of the spatial distribution.

30. The apparatus of claim 27 wherein users are allocated between beams.

31. The apparatus of claim 23 wherein the token or key is generated per connection.

32. The apparatus of claim 23 wherein the token or key is generated per data packet.

33. The apparatus of claim 23 wherein the token or key is placed in a least significant bit of the user data.

34. The apparatus of claim 23 wherein the token or key is placed in a control field of user data.

35. The apparatus of claim 23 wherein the cross-layer watermarking unit further comprises processing the user data in a layer higher than the higher watermarking layer.

36. The apparatus of claim 23 wherein the token or key is one of a signature unique to an originator, a signature unique to a radio modem, and a low data rate stream.

37. The apparatus of claim 23 wherein the watermarking is performed utilizing at least one of modulating carrier frequency within allowed limits, varying guard time intervals where the amount of the individual interval corresponds to a bit sequence of the watermark, introducing low level tones in the spectrum where each tone is associated with a watermark message, varying spectrum within allowed spectrum mask where a set of the filter coefficients is associated with a watermark message, using pseudo-randomly selected subcarriers in an orthogonal frequency division multiplex (OFDM) system where the selection is made according to watermarks being utilized.

38. The apparatus of claim 23 wherein the watermarking is performed utilizing at least one of, a dirty paper coding (DPC) technique for watermark encoding, embedding the token/key into a physical channel such that some of the redundancy bits of the channel code are replaced with bits relating to the token/key, transferring the token or key by initializing an forward error correction (FEC) shift register with the token or key prior to channel coding of the user data stream, changing the physical layer transmission format configuration where a set of the configuration corresponds to a watermark, modulating the amplitude in a constant envelope modulation scheme where the amount of the amplitude is an indication of bits of the watermark.

39. The apparatus of claim 23 wherein the communication is transmitted in an orthogonal frequency division multiplexing (OFDM) system.

40. The apparatus of claim 39 wherein the watermarking is performed by manipulating pilot sub carriers.

41. The apparatus of claim 39 wherein the watermarking is performed by modifying transmitted carrier frequency in a predetermined pattern.

42. The apparatus of claim 23 wherein the communication is transmitted in a code division multiple access system.

43. The apparatus of claim 42 wherein the watermarking is performed by stealing spreading code chips in a predetermined pattern.

44. The apparatus of claim 42 wherein the watermarking is performed by applying spreading code jitter with respect to the carrier frequency and frequency shift keying (FSK) modulation of watermark information on top of the jitter by placing a low frequency drift on the carrier frequency.