A very cool cryptography story to end the week with, as the nearly 450-year old coded writings of Rhode Island co-founder and 17th century theologian Roger Williams have finally been cracked by a Brown University team.

Historians call the now-readable writings the most significant addition to Williams scholarship in a generation or more. Williams is Rhode Island's founder and best known as the first figure to argue for the principle of the separation of church and state that would later be enshrined in the Bill of Rights.

His coded writings are in the form of notes in the margins of a book at the university's John Carter Brown Library. The nearly 250-page volume, "An Essay Towards the Reconciling of Differences Among Christians," was donated in the 1800s and included a handwritten note identifying Williams as the notes' author — though even that was uncertain at first.

A group including former library director Edward Widmer, Williams scholar and Rhode Island College history professor emeritus J. Stanley Lemons and others at Brown started trying to unravel the so-called "Mystery Book" a few years ago. But the most intense work began earlier this year after the university opened up the challenge to undergraduates, several of whom launched an independent project.

"No one had ever looked at it systematically like this in generations," said Widmer. "I think people probably looked at it and shrugged."
And once again math for the win.

Senior math major Lucas Mason-Brown, who has done the majority of the decoding, said his first instinct was to develop a statistical tool. The 21-year-old from Belmont, Mass., used frequency analysis, which looks at the frequency of letters or groups of letters in a text, but initially didn't get far.

He picked up critical clues after learning Williams had been trained in shorthand as a court stenographer in London, and built his own proprietary shorthand off an existing system. Lucas-Brown refined his analysis and came up with a rough key.

Williams' system consisted of 28 symbols that stand for a combination of English letters or sounds. How they're arranged is key to their meaning; arrange them one way and you get one word, arrange them another, you get something different. One major complication, according to Mason-Brown: Williams often improvised.

From there, Mason-Brown was able to translate scattered fragments, and the students determined there were three separate sections of notes. Two are Williams' writings on other books, a 17th century historical geography and a medical text. The third — and most intriguing — is 20 pages of Williams' original thoughts on one of the major theological issues of the day: infant baptism.
Some of the most famous minds in history kept their notes in coded fashion like this, precisely to keep knowledge and discussions of controversial topics out of the hands of people who would, you know, stone you or behead you for talking about things like "separation of church and state".  It's gratifying to know that centuries later, one American historical figure has a wealth of new knowledge to pass to us.

Now that deserves a round.