How does Xiaomi copy the access card to the mobile phone

Xiaomi copied the access card to the mobile phone. The mobile phone turns on the NFC function first, and copying the access card is not supported without the NFC function. Xiaomi wallet-copy the access card in Xiaomi key card. Only unencrypted access cards can be copied, and encrypted access cards cannot be directly copied to mobile phones. The method of simulating encryption access card to mobile phone: first, open a blank card in Xiaomi access card, and then go to the property to write the encrypted access card data into the blank card of mobile phone, and the encrypted access card will be copied to the mobile phone.