Protecting wireless local area networks from intrusion by eavesdropping on the eavesdroppers and dynamically reconfiguring encryption upon detection of intrusion

• US 20030202662A1
• Filed: 04/25/2002
• Published: 10/30/2003
• Est. Priority Date: 04/25/2002
• Status: Active Grant

• Current Assignee: Trend Micro Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: McBrearty, Gerald Francis, Shieh, Johnny Meng-Han, Mullen, Shawn Patrick, Tesauro, James Stanley
• Granted Patent: US 7,140,040 B2
• Time in Patent Office: Days
• US Class Current: 380/270
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/1475 Passive attacks, e.g. eavesdropping or listening without modification of the traffic monitored
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 12/121 Wireless intrusion detection systems [WIDS]; Wireless intrusion prevention systems [WIPS]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

The present invention involves the recognition that since an eavesdropper listening adjacent to a wireless LAN is likely to be mobile and operating on a short time cycle, he himself is likely to be wirelessly transmitting his test message. Consequently, the present invention provides the combination of apparatus for eavesdropping within an area layer adjacent to and surrounding the LAN area periphery for potential wireless transmissions of an intruder having a lower frequency within a level below the LAN frequency and addressed to the network location of any one of the computer terminals in the LAN; and an implementation responsive to said eavesdropping means for changing the encryption code of said encrypted wireless transmission upon the eavesdropping detection of a wireless transmission of said lower frequency addressed to a network location of one of the terminals in said LAN. There is the recognition that there are several factors contributing to the success of the process of the invention. It is likely that the intruder must send his message at a lower frequency than the 2.4 GHz frequency of the LAN area transmissions because the intruder will probably have to reach a base station tower over a longer distance or range than the adjacent target wireless LAN facility. This insures that the eavesdropping of the present invention will be at a lower frequency and, thus, not interfered with by the transmissions within the LAN.

Claims

1. In a wireless local area network (LAN) comprising a plurality of computer controlled terminals within a defined area, a system for the secure wireless transmission of data to and from computer terminals in the LAN comprising:

means for wireless transmission of data to and from computer terminals in the LAN at a selected LAN frequency level;

means for encrypting said wireless transmissions within said LAN;

means for eavesdropping within an area layer adjacent to and surrounding the LAN area periphery for wireless transmissions having a lower frequency within a level below the LAN frequency and addressed to the network location of any one of the computer terminals in the LAN; and

means responsive to said eavesdropping means for changing the encryption code of said encrypted wireless transmission upon the eavesdropping detection of a wireless transmission of said lower frequency addressed to a network location of one of the terminals in said LAN.

2. The wireless transmission system of claim 1 wherein said means for encrypting uses secret key encryption.

3. The wireless transmission system of claim 2 wherein the means for changing the encryption code dynamically reconfigures the secret key encryption upon said eavesdropping detection without interruption in transmissions within the LAN.

4. The wireless transmission system of claim 3 wherein said means for changing the encryption code reconfigures the secret key encryption independently of the previous secret key.

5. The wireless transmission system of claim 2 wherein said wireless transmission of data in the LAN has a selected frequency level in the order of 2.4 GHz.

6. The wireless transmission system of claim 5 wherein said means for eavesdropping detects wireless transmissions at a level in the order of 902 MHz.

7. A method for the secure wireless transmission of data to and from computer terminals in a wireless local area network (LAN) including a plurality of computer controlled terminals within a defined area comprising:

wirelessly transmitting data to and from computer terminals in the LAN at a selected LAN frequency level;

encrypting said wireless transmissions within said LAN;

eavesdropping within an area layer adjacent to and surrounding the LAN area periphery for wireless transmissions having a lower frequency within a level below the LAN frequency and addressed to the network location of any one of the computer terminals in the LAN; and

changing the encryption code of said encrypted wireless transmission upon the eavesdropping detection of a wireless transmission of said lower frequency addressed to a network location of one of the terminals in said LAN.

8. The method of claim 7 wherein said encrypting step uses secret key encryption.

9. The method of claim 8 wherein said step of changing the encryption code dynamically reconfigures the secret key encryption upon said eavesdropping detection without interruption in transmissions within the LAN.

10. The method of claim 9 wherein said step of changing the encryption code reconfigures the secret key encryption independently of the previous secret key.

11. The method of claim 8 wherein said wireless transmission of data in the LAN has a selected frequency level in the order of 2.4 GHz.

12. The method of claim 11 wherein said eavesdropping detects wireless transmissions at a level in the order of 902 MHz.

13. A computer program having code recorded on a computer readable medium for the secure wireless transmission of data to and from computer terminals in a wireless local area network (LAN) including a plurality of computer controlled terminals within a defined area comprising:

means for wireless transmission of data to and from computer terminals in the LAN at a selected LAN frequency level;

means for encrypting said wireless transmissions within said LAN;

means for eavesdropping within an area layer adjacent to and surrounding the LAN area periphery for wireless transmissions having a lower frequency within a level below the LAN frequency and addressed to the network location of any one of the computer terminals in the LAN; and

means responsive to said eavesdropping means for changing the encryption code of said encrypted wireless transmission upon the eavesdropping detection of a wireless transmission of said lower frequency addressed to a network location of one of the terminals in said LAN.

14. The computer program of claim 13 wherein said means for encrypting uses secret key encryption.

15. The computer program of claim 14 wherein the means for changing the encryption code dynamically reconfigures the secret key encryption upon said eavesdropping detection without interruption in transmissions within the LAN.

16. The computer program of claim 15 wherein said means for changing the encryption code reconfigures the secret key encryption independently of the previous secret key.

17. The computer program of claim 14 wherein said wireless transmission of data in the LAN has a selected frequency level in the order of 2.4 GHz.

18. The computer program of claim 17 wherein said means for eavesdropping detects wireless transmissions at a level in the order of 902 MHz.