What is the security of crypto postage stamp 3.0.? It is possible to read the code with NFC only, touching a closed wallet, not yet opened. At least I know right away if it's 6 or 5 digits.
exactly, unopened via NFC, you can ...
- verify its authenticity and
- the code itself
but the whale remains sleeping.
just by opening and scanning the qr-code or typing the 1- and A-code on the website, you awake the whale and reveal the colour of the stamp