boltcard/docs/CARD_PRIVACY.md

Card Privacy

Brief

The URI that is programmed into the card and returned as the NDEF consists of three parts.

1. The static part
2. The encrypted part
3. The authentication part

lnurlw://card.yourdomain.com/ln?p=A2EF40F6D46F1BB36E6EBF0114D4A464&c=F509EEA788E37E32  URI example

lnurlw://card.yourdomain.com/ln?p=                                &c=                  static

                                  A2EF40F6D46F1BB36E6EBF0114D4A464                     encrypted
                             
                                                                     F509EEA788E37E32  authentication

part	use
static	specfying the protocol and service location as a URI
encrypted	unique id and counter values encrypted by the card
authentication	a value to authenticate that the entire URI is as generated by the card

NXP NTAG424DNA features

Implementation