Fingerprint sensor & print verification location

[dmpyron]

Okay, I've read both the tutorial and, as much as I can, the app notes from ZianTech (not what I'd call a user's manual). My confusion is on where the finger print is verified. Is it done in the sensor or at the micro controller (or whatever computer)? If it's done at the sensor it seems I could just rip the sucker out and wire in my own controller and lie to the other end. I guess if I was running a two (or even three) factor authentication and just let it tell me, using 1:N, which print it is.

Am I correct in my interpretation? Or have missed something along the way? Not that that would be the first time

[adafruit_support_bill]

The recognition/verification is done in the sensor module itself. Given physical access to the module, someone familiar with the serial protocol could spoof it if they wanted.

[dmpyron]

Thanks. I guess, from reading what "they" provided, it seems possible that I might, from the view of the Arduino, have it tell me which # print it is? And then have my own list of "valid" numbers vs what the sensor can/might provide? It looks like I can make the request as either 1:1 (does this print # match the print you're looking at?) or 1:N (what number does the print you're looking at match?). If this is a correct interpretation, I might be able to have a limited number of enrolled prints (say six or seven) out of the ~170 available, with the numbers scattered out. Now the safe cracker has to figure out what to use, before "I" say "bugger off, at least for 10 minutes". Of course, I wouldn't tell him that, I'd just keep letting him try numbers. Of course, every failure just restarts the timeout clock.

But, given the availability of the RFID/NFC reader, why not use both? Then I've got "what you have" and "what you are". And I could toss in "what you know" (password/combination/etc) and feel pretty darned secure. Except for the oxygen lance that the guy brought in . Not that I know anything about that .

[adafruit_support_bill]

When you enroll the prints, you assign the numbers. So you can control what you consider to be 'valid' numbers. When the reader scans a print, it gives you a number along with a 'confidence level' indicating the quality of the match.

Adding an RFID would be still more secure. I have a lock-box tutorial in progress that requires a physical key, a PIN keypad entry and fingerprint scan before the box will open. Lacking those, a hacksaw or large hammer would suffice