Your code carries nothing about you
It is not derived from your name, birth date or phone. And it carries a check character that catches any single wrong character and any two swapped — so you are never marked present for someone else.
You pick your year and track once, and the subjects assign themselves. Your schedule, attendance, grades, wallet and card are all in one place.



It is not derived from your name, birth date or phone. And it carries a check character that catches any single wrong character and any two swapped — so you are never marked present for someone else.
The QR is signed and versioned. The moment you report it, every card printed before then stops working.
Every payment has a numbered receipt and every lesson has a line. You can check both whenever you want.
One step, and your subjects assign themselves after it.