Nomenclator Cipher

Nomenclator encryption uses a substitution of letters by words or words by letters or even groups of words.

It is possible to transform any word into a sentence and any sentence into word or letter. It all depends on the nomenclature used.

A classic idea is to replace each letter with a word that begins with the same letter (it is possible to try to make a sentence).

Nomenclator decryption requires knowing the nomenclature used (dictionary/alphabet/correlation table) and search and replace content.

The message does not have any characteristic and if the encoding is done right it can be perfectly intelligible.

However, in the event that a letter is replaced by a unique word, the message may comprise several repeated words.

It is impossible except in special cases.

In the case a letter is replaced by a single word, then replace each word with a random letter and perform attack using frequency analysis.

In the case where each letter has been replaced by a word beginning with the given letter, then replace each word with its first letter.