A friend of mine lost the password of a zip file of her. She remembers that the password contains digits only (that is, only 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9) and is 16 characters long or so. The digits in the password were chosen randomly, by randomly hitting keys. She kept her password in a TXT file, but the file is gone.
Is there any feasible way to recover the password? If so, how can we do that?
I read on the Internet that such long passwords can't be recovered, but I think our case is special because we know that the password is digit-only. We are laywomen in mathematics and can't estimate the amount of time needed to crack the password in our case. Should my friend simply let it go, or is it worth spending time and effort trying to recover the password?