Usually, amateur cryptanalysts began by compiling a list of known classic codes and cipher methodologies that can be used to encrypt secret messages. However, today powerful computers are used to analyse the ciphertext and look out for certain keys used to encrypt (possibly several times) the message.

None of these methods are guaranteed to work on the first try. Trial and errors are common, but with experience, seasoned cryptographers could recognise certain patterns that could provide some clue to the first step that should be taken.

Probable Word
When important messages are relayed, often unimaginative choice of words could give away the encryption, as specialists in the field of cryptography have amassed a set of most probable words as the nature of the message exhibits. For instance, in decoding love letters, frequency ordering looks for words such as ‘love, heart, fire, miss, life, light’ which are most frequently used. Hence it is important to rephrase messages before they are encrypted and transmitted.