How do computers help decode inscrutable ciphers?

Back in the 1940s, mathematician Warren Weaver made an audacious suggestion: what if translation was not a feat of literary theory and linguistics, but one of cryptography? Weaver suggested treating a foreign text as if it were a code to be broken. (This theory was the early basis of machine translation, a subfield of computational linguistics.) This metaphor of foreign language as code means that statistics and other tools of cryptography can be used to translate texts from one language to another. Today, it is the basis for programs like Google Translate.

This theory was also recently used to decode the Copiale Cipher, a manuscript from the 1800s. By making a machine-readable version of the text, a team of computational linguistics were able to run the characters through a software program that found patterns in the text, which were otherwise inscrutable. It turns out the manuscript was made by a secret society to explain their initiation rites. There are also portions that include political treatises on the natural rights of man. During the 1800s, secret societies of this sort flourished, and historians still speculate about their role in the French Revolution and the formation of the modern democratic state. The decoding of these documents could be very helpful to historians, as well as to linguists and cryptographers. For an academic explanation of the cryptographers work, see their complete paper.

There are many types of ciphers, but the most simple cipher replaces letters of the alphabet with other letters in order. If A is replaced with C, B is replaced with D, and so on. The Copiale Cipher relied on a technique called homophonic substitution, that uses more than the number of characters in the original alphabet to represent the sounds of text.

Of course, another manuscript still defies any code-breaking and translation attempts: the Voynich Manuscript from the early 1400s. Read more about it here.

What do you think of these code-breaking technologies?