Obscuring an accelerometer signal

• US 8,612,767 B2
• Filed: 06/25/2012
• Issued: 12/17/2013
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Gossweiler, Richard Carl III, Miller, James Brooks
• Primary Examiner(s): HENNING, MATTHEW T
• Application Number:
  US13/531,966
• Publication Number:
  US 20130111597A1
• Time in Patent Office: 540 Days
• Field of Search: None
• US Class Current: 713/183
• 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 21/60 Protecting data
• CPC Class Codes: G06F 21/82 Protecting input, output or interconnection devices
• CPC Class Codes: G06F 21/83 input devices, e.g. keyboards, mice or controllers thereof
• CPC Class Codes: G06F 2221/031 Protect user input by software means

Abstract

The present disclosure presents techniques for determining when to obscure an accelerometer signal from an accelerometer of a mobile device. The techniques include determining whether a user has been prompted to provide sensitive input data to the mobile device using an input device of the mobile device. When the user has been prompted to provide sensitive input data, the technique includes obscuring a portion of an accelerometer signal outputted from an accelerometer, and receiving the sensitive input data from the user at the input device while the accelerometer signal is obscured. In some embodiments, the accelerometer signal can be obscured by (i) switching the accelerometer 216 off, (ii) inserting a random noise signal into the accelerometer signal, (iii) masking the low-order bits of the accelerometer signal, (iv) passing the accelerometer signal through a filter, (v) actuating a vibrator of the mobile device, and/or (vi) otherwise degrading the accelerometer signal.

Claims

1. A computer-implemented method comprising:

determining, at a computing device including at least one processor and an accelerometer, that a user has been prompted to provide sensitive input data to the computing device;

when the user has been prompted to provide sensitive input data to the computing device, beginning to obscure a portion of an accelerometer signal output from the accelerometer to obtain an obscured accelerometer signal; and

receiving the sensitive input data from the user while the portion of the accelerometer signal is obscured.

2. The method of claim 1 further comprising:

determining that the user has finished entering the sensitive input data; and

ceasing to obscure the portion of the accelerometer signal when the user has finished entering the sensitive input data.

3. The method of claim 1, further comprising receiving, at the at least one processor, the obscured accelerometer signal.

4. The method of claim 1, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes turning off the accelerometer, and wherein the obscured accelerometer signal comprises no signal.

5. The method of claim 1, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes inserting a noise signal into the accelerometer signal to obtain the obscured accelerometer signal.

6. The method of claim 5, wherein the noise signal is based on one or more random numbers generated by a random number generator.

7. The method of claim 5, wherein the noise signal is a low-frequency range signal, and wherein the portion of the accelerometer signal that is obscured is a low-frequency range.

8. The method of claim 1, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes actuating a vibrator of the mobile device.

9. The method of claim 1, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes filtering the accelerometer signal.

10. The method of claim 9, wherein filtering the accelerometer signal includes applying a bit mask to the accelerometer signal.

11. A computing device comprising:

an input device configured to receive input data from a user;

an accelerometer module including an accelerometer; and

a processing device in communication with the input device and the accelerometer module and configured to determine whether the user has been prompted to provide sensitive input data to the computing device using the input device, and, when the user has been prompted to provide the sensitive input data to the computing device, to begin obscuring of a portion of an accelerometer signal output by the accelerometer to obtain an obscured accelerometer signal.

12. The mobile device of claim 11, wherein the processing device is further configured to determine that the user has finished entering the sensitive input data and to cease to obscure the portion of the accelerometer signal upon determining that the user has finished entering the sensitive input data.

13. The mobile device of claim 11, wherein the accelerometer module further includes a bit masking module that receives the accelerometer signal from the accelerometer and masks one or more low-order bits of the raw accelerometer signal to obtain the obscured accelerometer signal.

14. The mobile device of claim 13, wherein the accelerometer is a digital accelerometer and the accelerometer signal is a digital signal having a predetermined amount of bits, including the low-order bits.

15. The mobile device of claim 11, wherein the accelerometer module further includes a noise generation module configured to insert a noise signal into the accelerometer signal to obtain the obscured accelerometer signal.

16. The mobile device of claim 15, wherein the noise signal is a low frequency range signal, and wherein the portion of the accelerometer signal that is obscured is a low-frequency range.

17. The mobile device of claim 11, wherein the accelerometer module further includes a switch that selectively turns off the accelerometer to obscure the accelerometer signal, wherein the obscured accelerometer signal comprises no signal.

18. The mobile device of claim 11, wherein the processing device includes one or more processors.

19. A computer-implemented method comprising:

determining, at a processing device of a computing device, that a user has been prompted to provide sensitive input data to the computing device;

when the user has been prompted to provide sensitive input data to the computing device, beginning to obscure a portion of an accelerometer signal output from an accelerometer of the computing device to obtain an obscured accelerometer signal;

receiving, at the processing device, the obscured accelerometer signal;

receiving the sensitive input data from the user while the portion of the accelerometer signal is obscured;

determining, at the processing device, that the user has finished entering the sensitive input data; and

ceasing to obscure the portion of the accelerometer signal when the user has finished entering the sensitive input data.

20. The method of claim 19, wherein the processing device includes one or more processors.

21. The method of claim 19, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes inserting a noise signal into the accelerometer signal to obtain the obscured accelerometer signal.

22. The method of claim 21, wherein the noise signal is based on one or more random numbers generated by a random number generator.

23. The method of claim 21, wherein the noise signal is a low-frequency range signal, and wherein the portion of the accelerometer signal that is obscured is a low-frequency range.

24. The method of claim 19, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes actuating a vibrator of the mobile device.

25. The method of claim 19, wherein obscuring the portion of the accelerometer signal output from the accelerometer includes filtering the accelerometer signal.

26. The method of claim 25, wherein filtering the accelerometer signal includes applying a bit mask to the accelerometer signal.