tool can be used to decode Vigenère automately and to help decode subsitution cryptography(with some human knowledge).
python3 is required
python .\Decoder.py -i inputfile -t type
inputfile is the cryptography text file
type = 1 if decode subsititution
type = 2 if decode Vigenère
sub.txt is an attached testcase
we define meaningful n-gram:
Meaningful n-gram is a gram of n letters(n >= 2) which appear more than twice in a text, and if it is a sub-string of a k-gram (k > n), its appearence time must be different from the k-gram.(Which means it appears more than the k-gram) All gram we show to you is meaningful n-gram
You need to interate with the program with information and tips on screen.
vig.txt is an attached testcase
All this procedure can be run automately.
You can view the attached pdf file for the example detail.