Use serial nr for computer login?

Hi, I’ve watched this video in the link and wondering how to get the serial nr of my chip (I have a xnt)?

I have an ACR122U reader/writer, but I’m not getting the serial number displayed like in the video.
When I’m reading my chip with nfc tools the serial number is something with numbers, letters. This can’t be the correct number. I also can’t use this number for my win login (as in the video).

This video details how to simply use the ID of the RFID tag as a pin code or password. It works because the reader he’s using simply acts as an HID device (keyboard) and “types” out the UID of any tag it reads. Some readers will even press “enter” afterward for you… depending on features and configuration. The ACR122U is an actual PC/SC reader meant to be used for “real” RFID/NFC applications… so it doesn’t have this type of operating mode.

You can find these types of HID output readers on Amazon;

Once you get the reader connected via USB, scan your tag… it will output… something. It might be your xNT UID in hex format, or decimal, or some crazy binary format… but whatever it outputs, it will be consistent… so you can set your password or PIN using it and it will always output the same when you scan your xNT.

Just be aware, your UID is now your computer password… and your UID is easily scanned by anyone who gets close enough… it’s definitely not secure.

Maybe you could get one of the HID-type devices, scan your UID, and append a few characters on login. Sort of like 2-factor authentication.

You could also potentially get an Arduino Due, use it as an HID, hook up an RFID reader, and output a completely different password.

True. That would be sufficient if you had proper password tarpitting on your machine… but I don’t think Windows supports that. I think you could plug in an HID attack device that would just cycle through all possible 4 digits/characters pretty quickly :slight_smile: