I saw this movie years ago, like 4 years or more. I guess it's in french language. It's during WWII (I don't know, but it has something to do with Nazis).
It's about a french woman who's against the nazis. So the nazis want to catch her because of that and also because she knows some accounts numbers in Switzerland.
she lives with her father and her son (a boy of 12 maybe) who his father is American.
She let the boy memorize all the accounts numbers, in case she has been captured or killed and she calls the boy's father (which he didn't know that he has a son, cuz he didn't know that she was pregnant), anyway, she calls him and tell him to come to France for his son.
The nazis come and kill the grandfather, take her. The boy escaped somehow, and his father comes to help him to go to Switzerland, through the mountains alone. He survives and he goes to a Swiss bank with a man and tells all the numbers.