actually quadruple fool proof
1) must bring a real photo Id to polling station
2) must bring a snail mail voter registration card mailed to legal residence
3) only paper ballots used, hand counted and saved
4) the voter rolls are cross referenced with legal residency.,If one moves, you are automatically purged from old voting roll. Ditto for deceased. It’s a more stable society, so the number of people who move in any one year is tiny compared to US.
It’s difficult to get German citizenship (12 years plus need to meet some German “cultural” requirements). There are a few million non-citizens living in country, but they don’t have same ids as citizens so there is no way, a non-citizen resident could possibly get into a polling station.
Finally have 5 real poltical parties makes it difficult for the 2 big parties to collude in vote fraud.
I have heard that 1 in 5 move EACH year in America!