How can i encrypt data on adruino and send it to an nfc tag using pn532 nfc reader?

Is it posssible that the nfc reader can read encrypted data and decrypt it on the adruino ????. It is for an nfc based door security system which utilizes a nfc sticker tag that will be stuck on to the back of a phone which does not have nfc functionality.

I am just a newbie so maybe if i am wrong please correct me :slight_smile:

Depends on how it is encrypted, how fast it needs to decrypt it and what Arduino you have in mind. I'm assuming this will be something like a Mega or SAMD21; I wouldn't venture into this kind of territory with an old Nano or UNO.

It's for door security. I don't see any reason the MCU should be able to do 1000 Gigaencryption/decryption per seconds. The Nano and UNO are more than capable of doing encryption/decryption in software and still be able to provide the signal to open/lock the door in time.