Automated device access

1. A method for unlocking a locked computing device using a remote computing device, comprising:

at the locked computing device:

receiving a device identifier over a wireless communication protocol from the remote computing device, wherein the device identifier identifies the remote computing device;

determining, based on the device identifier, that the remote computing device is a trusted device;

causing at least a portion of an acoustic signal to be output from the remote computing device;

subsequent to the portion of the acoustic signal being output, and while at least a latter portion of the acoustic signal remains to be output and is being received:

receiving, via the wireless communication protocol and from the remote computing device, a digital copy of at least a portion of the acoustic signal from the remote computing device;

estimating a distance between the remote computing device and the locked device based on a delay between the acoustic signal output from the remote computing device and the digital copy of the at least a portion of the acoustic signal received, via the wireless communications protocol; and

unlocking the locked computing device if the distance is within a predetermined range.

2. The method of claim 1 , wherein the wireless communication protocol is a BLUETOOTH protocol.

3. The method of claim 1 , wherein the acoustic signal is based on at least a portion of an audio file stored at the locked computing device.

4. The method of claim 1 , wherein the acoustic signal includes frequencies greater than 20 kHz.

5. The method of claim 1 , wherein the acoustic signal includes frequencies between 18 kHz and 22 kHz.

6. The method of claim 1 , wherein the acoustic signal includes frequencies between 20 Hz and 20 kHz.

7. The method of claim 1 , wherein the acoustic signal is white noise generated with a processor of the locked computing device.

8. The method of claim 1 , wherein estimating the distance comprises:

calculating a propagation delay of the acoustic signal received at the locked computing device.

9. The method of claim 8 , wherein unlocking the locked computing device comprises:

in response to determining that the propagation delay is less than a threshold value:

unlocking the locked computing device.

10. A method for unlocking a locked computing device using a remote computing device, comprising:

at the remote computing device:

transmitting a device identifier over a wireless communication protocol to the locked computing device, wherein the device identifier identifies the remote computing device;

receiving, via a microphone and from the locked computing device, at least a portion of an acoustic signal; and

subsequent to the portion of the acoustic signal being received, and while at least a latter portion of the acoustic signal remains to be output from the locked computing device and is being received:

causing a digital copy of at least the portion of the acoustic signal to be transmitted to the locked computing device via the wireless communication protocol to enable the locked computing device to:

identify a distance between the remote computing device and the locked computing device, and

unlock the locked computing device in response to determining that the distance is within a predetermined threshold.

11. The method of claim 10 , wherein the wireless communication protocol is a BLUETOOTH protocol.

12. The method of claim 10 , wherein the acoustic signal is based on at least a portion of an audio file stored at the locked computing device.

13. The method of claim 10 , wherein the acoustic signal includes frequencies greater than 20 kHz.

14. The method of claim 10 , wherein the acoustic signal includes frequencies between 18 kHz and 22 kHz.

15. The method of claim 10 , wherein the acoustic signal includes frequencies between 20 Hz and 20 kHz.

16. The method of claim 10 , wherein the acoustic signal is white noise generated with a processor of the locked computing device.

17. The method of claim 10 , wherein estimating the distance comprises:

calculating a propagation delay of the acoustic signal received at the locked computing device.

18. The method of claim 17 , wherein unlocking the locked computing device comprises:

in response to determining that the propagation delay is less than a threshold value:

unlocking the locked computing device.

19. A machine-readable non-transitory storage medium storing instructions that, when executed by a processor included in a computing device, cause the computing device to carry out steps that include: at a locked computing device:

receiving a device identifier over a wireless communication protocol from a remote computing device;

determining if the device identifier is associated with a list of trusted devices;

transmitting a request to generate an acoustic signal;

causing at least a portion of an acoustic signal to be output from the remote computing device;

subsequent to the portion of the acoustic signal being output, and while at least a latter portion of the acoustic signal remains to be output and is being received:

receiving, via the wireless communication protocol and from the remote computing device, a digital copy of at least a portion of the acoustic signal from the remote computing device;

estimating a distance between the remote computing device and the locked computing device based on a delay between the acoustic signal output from the remote computing device and the digital copy of the at least a portion of the acoustic signal received, via the wireless communications protocol; and

unlocking the locked computing device if the distance is within a predetermined range.

20. The machine-readable non-transitory storage medium of claim 19 , wherein the wireless communication protocol is a BLUETOOTH protocol.

21. The machine-readable non-transitory storage medium of claim 19 , wherein the acoustic signal is based on at least a portion of an audio file stored at the locked computing device.

22. The machine-readable non-transitory storage medium of claim 19 , wherein the acoustic signal is white noise generated with a processor of the locked computing device.

23. The machine-readable non-transitory storage medium of claim 19 , wherein:

estimating the distance comprises calculating a propagation delay of the acoustic signal received at the locked computing device; and

unlocking the locked computing device when the propagation delay is less than a threshold value.

24. A machine-readable non-transitory storage medium storing instructions that, when executed by a processor included in a computing device, cause the computing device to carry out steps that include: at a remote computing device:

transmitting a device identifier over a wireless communication protocol to a locked computing device, wherein the device identifier identifies the remote computing device;

receiving, via a microphone and from the locked computing device, at least a portion of an acoustic signal; and

subsequent to the portion of the acoustic signal being received, and while at least a latter portion of the acoustic signal remains to be output from the locked computing device and is being received:

causing a digital copy of at least the portion of the acoustic signal to be transmitted to the locked computing device via the wireless communication protocol to enable the locked computing device to:

identify a distance between the remote computing device and the locked computing device, and

unlock the locked computing device in response to determining that the distance is within a predetermined threshold.

25. A system, comprising:

a locked computing device;

a remote computing device in communication with the locked computing device over a wireless communication protocol wherein the locked computing device is configured to:

receive a device identifier over the wireless communication protocol from the remote computing device;

determine if the device identifier is associated with a list of trusted devices;

transmit a request to generate an acoustic signal;

cause at least a portion of an acoustic signal to be output; and

subsequent to the portion of the acoustic signal being output, and while at least a latter portion of the acoustic signal remains to be output and is being received:

receive, via the wireless communication protocol and from the remote computing device, a digital copy of at least a portion of the acoustic signal from the remote computing device;

estimate a distance between the remote computing device and the locked computing device based on a delay between the acoustic signal output from the remote computing device and the digital copy of the at least a portion of the acoustic signal received, via the wireless communications protocol; and

unlock the locked computing device if the distance is within a predetermined range; and

the remote computing device is configured to:

transmit the device identifier over the wireless communication protocol to the locked computing device;

receive, via a microphone and from the locked computing device, at least a portion of the acoustic signal; and

subsequent to the portion of the acoustic signal being received, and while at least the latter portion of the acoustic signal remains to be output from the locked device and is being received:

cause the digital copy of at least the portion of the acoustic signal to be transmitted to the locked computing device via the wireless communication protocol to enable the locked computing device to unlock.