Yes, it's very likely software-based solution the likes many countries have (Smart-ID, BankID and others). It's in many ways just easier that way. Better? I don

Yes, it's very likely software-based solution the likes many countries have (Smart-ID, BankID and others). It's in many ways just easier that way. Better? I don't think so. It is possible to do it without an "app" by using SIM applets. The keys are stored on the SIM card, it acts as an HSM. Estonian Mobile-ID has been implemented using that and it works even on feature phones. There are a few papers about the system if one searches around and if you're interested.