Right now I'm working on a door lock that uses NFC to unlock. My goal is to build a more passive system than NFC requiring me to do nothing and have it unlock as I approach? I don't mind carrying a device (or phone) that interacts with the door. I just want to be able to do it without interacting with the device or door. I want it to unlock as I walk up.
What are options do I have to achieve something like this and how secure are they?
Thanks for any ideas.
Retinal scans are pretty secure, doubly so if you backed them with a thumbprint reader.
Interesting, will look into those.
Have you considered using OPENCV for facial tracking and recognition?
Face detection is pretty straight forward, the facial recognition is still a bit high on false positives.
Used in combination with finger/thumb, iris, or even voice it gets very accurate. Thumb, finger IRIS are not totally passive (although you can have your hands full of bags of groceries and put your eye up there or speak a command.)
I don't believe the Arduino can handle the input, but a RasPI or maybe a old PC, the face detection is doable on a low end, but the facial recognition requires a bit more, so you'll need something with more power to work with the Arduino. (IMHO). I'm still pretty new at Arduino, OPENCV, etc.
I'm thinking (not done any research yet until now) about a similar system, mostly passive, I was thinking about just doing the face tracking, take a picture and unlock the gate. Maybe track the vehicle's license plate. I understand license plates are pretty easy to grab and record, easier than faces.
What NFC stuff are you using/ researching?
Are you going with a NFC shield or pre-build lock-controller device or just a stand alone NFC reader?
Are you following any specific instructions or guide?
Have you considered bluetooth "pairing" to unlock the door?
@robtillaart: I did but didn't know bluetooth's ability to negotiate something like this without interaction from me. Would I use my phone or a standalone device?
You should have an APP on your phone that does the negotiation.
you could use a challenge/response (CR) method
The Arduino tries to connect and sends a challenge (a number) and the APP calculates the response from this number by means of a secret formula and sends it back.
e.g. a simple secret formula could be : take the odd digits of the challenge and multiply them, add 3 random numbers before and 3 random numbers after it and send it back.
challenge = 12345678
response = 135*7 = 105 + 6 random digits => 746105782
(note this is not a very good CR formula)
Drawback is that bluetooth must be kept on ...
BopRock:
@robtillaart: I did but didn't know bluetooth's ability to negotiate something like this without interaction from me. Would I use my phone or a standalone device?
If using Bluetooth Smart/Low Energy, the Device can connect directly with the App, no need to pair with your phone. So If you come around and it connects, done.
But better have an Iphone, Android BLE Support is still pretty buggy... They announced to support it the middle of this year, BLE was released 2009 