How to deal with overprotective dad?

(srry for it being long) hey i'm an 18 year old guy who is really interested in this girl i've been hanging out with who is 17 . shes never had a boyfriend before and here is why, her dad is extremely over protective and made her and a recent guy break up a little over a month ago, idk why i didn't want to step over any boundries and ask but it really affected and makes her sad and upset, if she does anything alone with a guy then he doesn't like it, now she said to wait till she's 18 wich is in a month when she has more freedom to date but she is really traditional and wants me to ask her dad if i can date her, she dated that one guy for a couple of weeks so that means he must have asked to and the dad said ok so the previous boyfriend may have done something that idk, i just didn't want to go deep into it, and we can't date behind the dad's back because if he ever found out then he would nvr let me near her again and that would hurt her more. i've told her that if she wanted to, sit down and just talk about it she said yes so i need to now wat to say to her and wat advice to give any help would be great becuase i really care for this girl