Is it possible to copy the signature and READ_SIG command of NTAG21x?
There is the signature function on NTAG21x for a brand protection.
However I think if other malign IC maker copy the NTAG21x including the signature and READ_SIG, we cannot judge if the IC is made by NXP or not.
I think we can verify it if the signature is generated by UID and private key.
Best Regards,
Naoto.
Dear Naoto Ikeda, Hope you are doing great, Each NTAG supporting the originality signature holds a 32-byte cryptographic signature based on elliptic curve cryptography. This signature can be retrieved using a dedicated
command and can be verified using the corresponding ECC public key in the NFC
device. please check the AN11350 NTAG Originality Signature Validation here is the explanation about this procedure hopefully it will answer your question.
BR
Jonathan