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Can the data from a fingerprint scanner be used to recreate my print? © iStock

Can the data from a fingerprint scanner be used to recreate my print?

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Biometric scanners retain your fingerprint data as binary code, but can the machine be tricked? Your print stolen?

Asked by: Kate Woods, Hertfordshire


When your finger is first scanned, the print is turned into a much-simplified numerical description. When you present your finger again, it's the numbers that are compared. These numbers don't contain enough information to reconstruct the original print, but the reference print stored in the database probably does. If not a perfect copy of the original fingerprint, then at least one that would fool that particular fingerprint scanner.

Fingerprint recognition systems need to allow for the fact that the live finger being scanned may be presented at a different angle to the original. For this reason, the matching algorithm will normally rotate and adjust the live scan image as it searches for the best fit with each of the records in its database.

When it finds a match, the number of matching features on the scanned print, as well as the distances between them, will be scored and weighted to give an overall match value. If this crosses a predetermined threshold, the print will be recognised.


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luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.


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