Thanks for the title.
Actually I used the method written in the paper and with lots of optimizations I can now crack this file in around 12 minutes and with some additional brain power even after 5 minutes with one additional information in 30 secs.
If I have only 5 files, it takes a bit longer, but is still possible.
The program will be released as an addition to pkcrack later.
Brain versus Computer brute force *g*.
It was really surprising when I saw that the password was only 8 characters.
With this method I can also crack infinity long passwords that will never be cracked via bf though, which was the reason why I implemented the paper.
Best Wishes and Take Care,
Fabian