BlueID technology facilitates this ID. As a background software, BlueID generates individual certificates. It connects and secures the link between a hardware manufacturer’s device and a service provider’s app. In that, it works with Bluetooth low energy and both, with or without internet access. Even if it did not go exactly like this in your case, it surely did for the majority of the passengers around you. According to the statistics, around 50 million Germans have their smartphone at hand which makes it very likely that the majority of your fellow travellers today have one too. Almost 90 per cent of them will have booked their trip with their phone and only 20 per cent of them were checked in by a human being, whereas the rest performed a different kind of self check-in.