Originally Posted by
Rami Tamimi
...but they don't validate your entry via the chip, they do it via scanning the barcode, which brings up your "file", which contains fingerprints.
You're right, I was responding to a question that wasn't asked.
It doesn't just bring up a file with your fingerprints; it would be folly other than to bring up the whole file including parsing the validity of the passport.
The barcode likely serves to access the file, the fingerprints to prove it's you. In between the database is querried to ensure the passport is legit. And if it's been cancelled by the issuing country then I'm sure it would preclude admission.