Fake IDs are hard to weed out. But the right ID or passport scanner solution, deployed at border control and security touchpoints, can catch the fakes without negatively impacting passenger flow.
People Also Ask
The officer scans your passport to see basic info: Name, date of birth, country of citizenship, etc. The passport page containing that basic info also shows a 'code key' that, when scanned, grants access to the chip which contains the same info.
When a CAT unit is in use, a TSA officer will ask travelers to provide their photo IDs. The officer will insert each photo ID into the CAT unit where the ID is scanned and analyzed.
Upon arrival, go through the immigration and passport control area of the airport. Passengers are split into multiple lines. There is generally a line for host country nationals (people with a passport from that country), sometimes a line for citizens of the region (EU, ECOWAS, etc), and non-immigrant visitors.
You have to solve the passport verification issue before you can travel out of your country. To do otherwise is to risk arrest on arrival and deportation.
Taking your question more literal: there is not necessarily a passport check at the gate. That happens on and off, depending seemingly on mood, airline, and time of the day. But there is always a check before you get a boarding pass.