Cryptanalysis of substitution type ciphers

Vigenere

           1. determing the key size
                  a) method of Babbage and Kasiski
                      repeated occurrence of strings
                      example 
                  b) Friedman's method - index of coincidence


           2. determining the key
                  division of cipher text into substrings
                  determining relative shifts
                      index of mutual coincidence

next back
menu

Cryptanalysis of substitution type ciphers

Vigenere 1. determing the key size a) method of Babbage and Kasiski repeated occurrence of strings example b) Friedman's method - index of coincidence 2. determining the key division of cipher text into substrings determining relative shifts index of mutual coincidence

Vigenere
1. determing the key size a) method of Babbage and Kasiski repeated occurrence of strings example b) Friedman's method - index of coincidence 2. determining the key division of cipher text into substrings determining relative shifts index of mutual coincidence