The format of the data on a passport is unified (https://en.wikipedia.org/wiki/Machine-readable_passport https://en.wikipedia.org/wiki/Machine-readable_passport

The format of the data on a passport is unified (https://en.wikipedia.org/wiki/Machine-readable_passport https://en.wikipedia.org/wiki/Machine-readable_passport) but the problem is to make sure that the one who presents this string of data is actually the one it belongs to.