Detection of peripheral device manipulation
A computer-implemented method and transaction terminal is disclosed. The method comprises capturing, by an imaging device, a first image of an internal region of an apparent peripheral device of the transaction terminal, calculating, by a processor of a transaction terminal, a first amount of change between the first image and a baseline image of the internal region, capturing, by the imaging device, at least one further image of the internal region, for each further image, calculating, by the processor, a second amount of change between the further image and a respective baseline image of the internal region, and when at least two consecutive values of the first and/or second amount of change are below a predefined value, determining that the imaging device is in a dummy peripheral device to prevent detection of a foreign object in an active peripheral device of the transaction terminal.
1. A computer-implemented method for determining that an imaging device for a peripheral device of a transaction terminal is in a dummy peripheral device to prevent detection of a foreign object in an active peripheral device of the transaction terminal, comprising the steps of:
capturing, by an imaging device, a first image of an internal region of an apparent peripheral device of the transaction terminal;
calculating, by a processor of a transaction terminal, a first amount of change between the first image and a baseline image of the internal region;
capturing, by the imaging device, at least one further image of the internal region;
for each further image, calculating, by the processor, a second amount of change between the further image and a respective baseline image of the internal region; and
when at least two consecutive values of at least one of the first and second amount of change are below a predefined value, determining that the imaging device is in a dummy peripheral device to prevent detection of a foreign object in an active peripheral device of the transaction terminal.
2. The method as claimed in claim 1 , further comprising:
determining, by the processor, that the imaging device is in the dummy peripheral device when at least two consecutive values of at least one of the first and second amount of change are zero.
3. The method as claimed in claim 1 , further comprising:
calculating, by the processor, the first amount of change as an overall percentage change between the first image and the baseline image; and
calculating, by the processor, the second amount of change as an overall percentage change between each further image and each respective baseline image.
4. The method as claimed in claim 1 , further comprising:
determining, by the processor, that the imaging device is in the dummy peripheral device when at least five consecutive values of at least one of the first and second amount of change are below the predefined value.
5. The method as claimed in claim 1 , further comprising:
after capturing the first image, determining, by the processor, that the foreign object is not present in the first image by comparing the first image with the baseline image.
6. The method as claimed in claim 1 , further comprising:
after capturing each further image, determining, by the processor, that the foreign object is not present in the further image by comparing the further image with the respective baseline image.
7. The method as claimed in claim 5 , whereby comparing comprises:
calculating, by the processor, a difference between first pixel values associated with pixels of said first image and second pixel values associated with corresponding pixels of the baseline image, thereby obtaining a plurality of difference values; and
after calculating said difference, calculating, by the processor, a first preset value of two preset values for difference values of the plurality of difference values that exceed the first predetermined threshold.
8. The method as claimed in claim 7 , whereby determining that the foreign object is not present in the first or further image comprises:
determining that the foreign object is not present in the first or further image when less than a predefined amount of the first preset value exceeds a second predetermined threshold in at least one region of interest associated with the internal region.
9. The method as claimed in claim 8 , further comprising:
determining that the foreign object is not present in the first or further image when a predefined percentage of the first preset value does not exceed the second predetermined threshold in the at least one region of interest.
10. The method as claimed in claim 7 , further comprising:
calculating said first preset value by applying, by the processor, a thresholding algorithm to the plurality of difference values.
11. The method as claimed in claim 7 , further comprising:
calculating said difference to obtain the plurality of difference values by subtracting, by the processor, all pixel values associated with the pixels of the first image from all corresponding pixel values associated with the pixels of the baseline image, or vice versa.
12. The method as claimed in claim 7 , further comprising:
generating, by the processor, a difference image comprising pixels each having a pixel value equal to one of the plurality of difference values.
13. The method as claimed in claim 7 , further comprising:
generating, by the processor, a threshold image comprising pixels having values equal to the first preset value and pixels having values equal to a second preset value of the two preset values, the second preset value representing difference values of the plurality of difference values that do not exceed the first predetermined threshold.
14. The method as claimed in claim 1 , further comprising:
capturing, by the imaging device, said first image and each further image after a transaction has been conducted on the transaction terminal.
15. The method as claimed in claim 1 , further comprising:
capturing, by the imaging device, an original baseline image with the imaging device during startup of the active peripheral device on the transaction terminal; and
when the foreign object is not determined as being present in the first image, replacing the original baseline image with said first image, thereby providing an updated baseline image.
16. The method as claimed in claim 15 , further comprising:
for each further image, when the foreign object is not determined as being present in the further image, replacing the updated baseline image with the further image.
17. The method as claimed in claim 1 , further comprising:
responsive to determining that the imaging device is in the dummy peripheral device, issuing, by the processor, an alert.
18. The method as claimed in claim 1 , whereby the active peripheral device is a card reader and the foreign object is a card skimming device.
19. A transaction terminal, comprising:
an imaging device configured to capture images of an internal region of a peripheral device; and
at least one processor comprised within or communicatively coupled to the peripheral device and coupled to the imaging device to receive the captured images, the processor configured to:
calculate a first amount of change between a first image of an internal region of an apparent peripheral device captured by the imaging device and received from the imaging device and a baseline image of the internal region;
for each further image captured of the internal region by the imaging device and received from the imaging device, calculate a second amount of change between the further image and a respective baseline image of the internal region; and
determine that the imaging device is in a dummy peripheral device to prevent detection of a foreign object in an active peripheral device of the transaction terminal when at least two consecutive values of at least one of the first and second amount of change are below a predefined value.