hacking vigenere cipher tool
Here is sample application for decrypting Vigenere ciphered text using algorythm described http://practicalcryptography.com/cryptanalysis/stochastic-searching/cryptanalysis-vigenere-cipher/
First it try to determine key length searching for maximal Index of Occurence for keys with length 2-12 Then for every char in key it calculated average Chi-Square between character frequencies comparable to english alphabet frequencies. Lower value taken as result.
Linux - type 'make' in folder with Makefile Windows - open .sln file in Visual Studio 2019, build and run
Command line options: $ Vigerere <test|decrypt> [input text file]
$ Vigenere test
Will start run of unit test to test components of application. Running test requires presense of following files with test vectors in binarie's folder:
- test2.enc
- test2.key
- test2.txt
- ioc3.txt
$ Vigenere decrypt [input file name]
Decrypt provided file and show result to console output