RAW SENSOR INPUT ENCRYPTION FOR PASSCODE ENTRY SECURITY

1 . A method of operating a mobile device to prevent an unauthorized capture of a passcode entry in a financial transaction, the method comprising:

initiating the financial transaction when a card reader, coupled to the mobile device, detects swiping of a payment card from a user;

presenting a passcode entry interface on a touch screen of the mobile device for the user to input a passcode;

during the presenting of the passcode entry interface, receiving a touch event from the touch screen;

encrypting a location of the touch event, indicative of where a touch by the user occurred on the touch screen; and

transmitting the encrypted location to an external system over a network, to cause the external system to authenticate the user by deciphering the passcode based at least in part on the encrypted location of the touch event.

2 . The method of claim 1 , further comprising encrypting a metadata entry of the touch event together with the location of the touch event.

3 . The method of claim 1 , wherein encrypting the location of the touch event comprises using asymmetric cryptography.

4 . The method of claim 1 , wherein encrypting the location of the touch event is performed in batch with encrypting a location of another touch event.

5 . The method of claim 1 , further comprising transmitting data indicating a screen geometry of the touch screen to the external system.

6 . A method of operating an electronic device to prevent an unauthorized capture of a passcode in a financial transaction, the method comprising:

presenting a passcode entry interface on the electronic device for a user to input a passcode entry;

receiving an input event from a sensor of the electronic device, wherein the input event is indicative of at least part of the passcode entry by the user and includes at least a sensor value as measured by the sensor;

encrypting the sensor value of the input event; and

transmitting the encrypted sensor value to an external system over a network to cause the external system to decipher the passcode entry based at least in part on the encrypted sensor value.

7 . The method of claim 6 , further comprising transmitting an interface configuration of the passcode entry interface to the external system, wherein the interface configuration specifies a mapping between sensor values from the sensor and a set of characters for composing the passcode entry.

8 . The method of claim 7 , wherein the interface configuration includes a geometric characteristic of the passcode entry interface as presented on a touch screen of the electronic device.

9 . The method of claim 7 , further comprising encrypting the interface configuration prior to transmitting the interface configuration.

10 . The method of claim 7 , further comprising generating a randomized arrangement for the passcode entry interface; wherein the randomized arrangement is recorded as part of the interface configuration.

11 . The method of claim 6 , further comprising transmitting a screen geometry of a display device of the electronic device to the external system, wherein the passcode entry interface is displayed on the display device.

12 . The method of claim 6 , wherein encrypting the sensor value of the input event comprises using white box cryptography.

13 . The method of claim 6 , wherein encrypting the sensor value of the input event comprises using asymmetric cryptography.

14 . A method of operating a computing system for deciphering a passcode based at least in part on sensor inputs, the method comprising:

receiving an encrypted sensor input value from an electronic device, wherein the encrypted sensor input value corresponds to a user interaction with a passcode entry interface on the electronic device;

decrypting the encrypted sensor input value to determine a user input event;

accessing an interface configuration of the passcode entry interface that specifies a mapping between sensor input values and a set of characters for composing the passcode; and

deciphering a passcode entry by a user based at least in part on the user input event and the interface configuration.

15 . The method of claim 14 , further comprising generating the interface configuration specifically for a session with a user interacting with the passcode entry interface.

16 . The method of claim 15 , wherein generating the interface configuration includes generating the interface configuration as a randomized arrangement of interactive buttons; and wherein accessing the interface configuration includes accessing locations of the interactive buttons.

17 . The method of claim 16 , further comprising transmitting the interface configuration to the electronic device to enable a display of the passcode entry interface on the electronic device.

18 . The method of claim 14 , wherein accessing the interface configuration includes receiving an encrypted configuration from the electronic device and decrypting the encrypted configuration as the interface configuration.

19 . A computer program product encoded on a computer storage medium, operable when executed by a processor, wherein the computer program product is operable to:

present a passcode entry interface on an electronic device for a user to input a passcode entry;

receive an input event from a sensor of the electronic device, wherein the input event is indicative of at least part of the passcode entry by the user and includes at least a sensor value as measured by the sensor;

encrypt the sensor value of the input event; and

transmit the encrypted sensor value to an external system over a network to cause the external system to decipher the passcode entry based at least in part on the encrypted sensor value.

20 . An electronic device comprising:

a memory;

a display device to present a passcode entry interface for a user to input a passcode entry;

a sensor to store a sensor input sequence in the memory, wherein the sensor input sequence is indicative of a user interaction with the passcode entry interface; and

a processor to encrypt a sensor entry of the sensor input sequence and to transmit the encrypted sensor entry to a remote system over a network to decipher the passcode entry by the user.

21 . A computer server system comprising:

a network interface through which to receive a sensor input sequence from an electronic device, wherein the sensor input sequence is indicative of a user interaction with a passcode entry interface on the electronic device;

a security component to decrypt an encrypted sensor entry of the sensor input sequence; and

a processor configured to decipher a passcode entry by the user based on at least the decrypted sensor entry and data indicative of a geometry of the passcode entry interface.