Method and/or apparatus for implementing security in keyboard-computer communication

• US 6,912,605 B1
• Filed: 03/29/2002
• Issued: 06/28/2005
• Est. Priority Date: 03/29/2002
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Wright, David G.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Sorrell, Eron
• Application Number:
  US10/113,180
• Time in Patent Office: 1,187 Days
• Field of Search: 710/2, 710/58, 710/60, 710/62, 710/65, 710/67, 710/73, 713/202, 713/401, 713/501, 341/29
• US Class Current: 710/60
• CPC Class Codes: G06F 21/556 involving covert channels, i.e. data leakage between processes inhibiting the analysis of circuitry or operation with measures against power attack G06F21/755
• CPC Class Codes: G06F 21/83 input devices, e.g. keyboards, mice or controllers thereof

Abstract

A method for altering timing between transmissions of an input device comprising the steps of (A) receiving a plurality of inputs from the input device, (B) altering the timing between the inputs and (C) presenting the altered inputs in a potentially insecure environment.

Claims

1. A method for altering timing between transmissions of a wireless input device of a personal computer (PC) comprising the steps of:

(A) receiving a plurality of inputs from said wireless input device, wherein each of said inputs are separated by one of a plurality of inter-keystroke timing intervals;

(B) altering the timing between said inputs to obscure said inter-keystroke timing intervals and enhance security of said wireless input device; and

(C) presenting said altered inputs to said personal computer through a wireless environment.

2. The method according to claim 1, wherein said input device comprises a human interface device (HID).

3. The method according to claim 1, wherein step (B) comprises altering the inter-keystroke timing intervals between each of said inputs.

4. The method according to claim 1, wherein said wireless input device comprises a wireless keyboard configured to modify timing of keystroke transmissions in addition to normal wireless transmissions and firmware security techniques.

5. The method according to claim 1, further comprising the steps of:

introducing dummy keystrokes into a keystroke sequence, wherein said dummy keystrokes convey other than hidden data.

6. The method according to claim 1, wherein step (B) comprises:

deliberately delaying a keystroke transmission to increase the probability that the delayed keystroke is combined with another keystroke as a single transmission.

7. The method according to claim 1, further comprising:

periodically transmitting data packets regardless of whether or not data is being transmitted, wherein said periodic transmission obscures the timing of the transmission of data that is transmitted.

8. The method according to claim 1, further comprising:

starting and stopping said method in accordance with predetermined criteria.

9. The method according to claim 1, further comprising:

starting and stopping said method in response to commands from a host computer.

10. The method according to claim 1, further comprising:

issuing by a computer commands to a human interface device (HID) to start or stop altering the timings of transmissions in response to the sensitivity or insensitivity of data being transmitted by the HID.

11. The method according to claim 1, further comprising:

inserting a pause after each keystroke.

12. The method according to claim 11, wherein said pause is varied after each keystroke.

13. The method according to claim 1, wherein said step (B) is activated only at particularly vulnerable times.

14. The method according to claim 13, wherein a host activates/deactivates step (B).

15. An apparatus comprising:

a wireless input device of a personal computer (PC) configured to (i) receive a plurality of inputs each separated by one of a plurality of inter-keystroke timing intervals, (ii) alter timing between said inputs to obscure said inter-keystroke timing intervals and enhance security of said wireless input device, and (iii) present said altered inputs to said personal computer through a wireless environment.

16. The apparatus according to claim 15, wherein said device is further configured to generate one or more dummy keystrokes and present said dummy keystrokes at random intervals.

17. The apparatus according to claim 15, wherein said device is configured to alter said timing such that said timing altered inputs are presented at regular intervals.

18. The apparatus according to claim 15, wherein said device is only activated at particularly vulnerable times.

19. The apparatus according to claim 15, wherein said device is implemented in an integrated circuit selected from the group consisting of firmware and a state machine.

20. An apparatus for altering timing between transmissions of a wireless input device of a personal computer (PC) comprising:

means for receiving a plurality of inputs from said wireless input device, wherein each of said inputs are separated by one of a plurality of inter-keystroke timing intervals;

means for altering timing between said inputs to obscure inter-keystroke timing intervals and enhance security of said wireless input device; and

means for presenting said altered inputs to said personal computer through a wireless environment.