How does the NTAG originality signature work?

[ahaensel]

According to the documentation the originality signature is the UID signed with the NXP private key.

Both the UID and the signature are readable.

If someone fakes a tag and makes the UID and the signature identical to the original tag, how would I be able to detect the forgery?

[Jonathan_Iglesias]

Please check this post and the documents links in it, there you can find the explanation on how this works, also it is important you know how an asymmetry cryptography works.

https://community.nxp.com/message/1119360?commentID=1119360&et=watches.email.thread#comment-1119360 

BR

Jonathan