You can break substitution ciphers pretty trivially, just using a simple hill climbing algorithm see http://practicalcryptography.com/cryptanalysis/stochastic-s

You can break substitution ciphers pretty trivially, just using a simple hill climbing algorithm see http://practicalcryptography.com/cryptanalysis/stochastic-searching/cryptanalysis-simple-substitution-cipher/ http://practicalcryptography.com/cryptanalysis/stochastic-se... If your cipher is at least 100 characters this will solve it very quickly.