Tamper detection using ITO touch screen traces
Aspects of the technology provide an electronic device having a touch display and a method of detecting any possible tampering with the electronic device using the same ITO traces of a conductive grid of the touch display that are used to drive the touch display for displaying information and/or sensing touch inputs.
1. A method of detecting a tampering event at a device having a touch screen, the touch screen including a conductive grid of Indium-Tin-Oxide (ITO) traces that are configured to have their electrical properties altered when the touch screen receives a touch input and their conductive properties altered due to the tampering event, and a touch controller configured to detect the altered electrical and conductive properties, the method comprising:
electrically scanning, by the touch controller, the ITO traces of the touch screen to detect the altered electrical properties of the ITO traces to detect the touch input;
electrically scanning, by the touch controller, the ITO traces of the touch screen to detect the altered conductive properties of the ITO traces;
in response to detecting that the conductive properties of at least one of the ITO traces of the touch screen has been altered, determining that the tampering event comprising a physical manipulation of the touch screen occurred; and
disabling operation of the device upon determining that the tampering event occurred, whereby the touch screen is not able to be used as a point of entry to introduce a security vulnerability into the device.
2. The method according to claim 1 , wherein the electrical scanning of the ITO traces to detect the altered conductive properties of the at least one of the ITO traces is performed after at least one instance of electrical scanning of the ITO traces to detect the touch input.
3. The method according to claim 1 , wherein the physical manipulation is by one of a merchant, a customer or an unauthorized agent.
4. The method according to claim 1 , wherein the altered electrical properties for detecting a touch is a change in capacitance at point of contact between at least one driving trace and at least one sensing trace of the ITO traces of the touch screen.
5. The method according to claim 1 , wherein the electrical scanning of the ITO traces for detecting the touch is a sequential scan of the ITO traces of the touch screen.
6. The method according to claim 1 , wherein
the electrical scanning of the ITO traces to detect the touch is performed at a first sampling rate, and
the electrical scanning of the ITO traces to detect the altered conductive properties of at least one of the ITO traces is performed at a second sampling rate.
7. The method according to claim 6 , wherein the second sampling rate is less than the first sampling rate.
8. The method according to claim 1 , wherein the disabling comprises at least one of:
deleting any encryption key stored on the device for use in completing a financial transaction;
locking the device so that no financial transaction can be completed using the device; or
shutting down the device.