Via Episcopal Cafe’s The Lead and TitusOneNine, the Telegraph and the Independent carry the story of the Rev. Prof. Kenneth Newport of Liverpool Hope University has broken the encryption on Charles Wesley’s handwritten journal. The cleartext journal offers insight into the Wesley brothers’ relationship, Charles’s personality and concerns for Methodism, Anglicanism and the progress of Islam into Europe.
It’s a basic principle of cryptography that you need three things to decrypt an encrypted text: the ciphertext itself, the algorithm used to encrypt it and the key applied. You need all three items in order to render the cleartext. The ciphertext is the encrypted journal itself, all one thousand hand-written pages.
Contemporary to Charles Wesley was John Byrom, professor at Oxford and developer of a method for stenographic shorthand. The shorthand was taught at Cambridge and Oxford and used in official government work. The method is his algorithm for encryption: take a clear sentence and, writing it in shorthand, you have a lightly “encrypted” text. The algorithm can get you from one to the other.
The trick, of course, is in determining the key. WIthout the key, having the ciphertext and algorithm are impotent. But, Prof. Newport eventuallty figured out the key:
The breakthrough came when he discovered that Wesley had rendered part of the scriptures in shorthand and was able to compare the abbreviations against the King James Bible. “I was determined to unlock it. Charles was a great man, with insights that remain important for us today,” he said.
Charles Wesley used the same algorithm and key for writing the New Testament in shorthand. With a cleartext, ciphertext and the algorithm, Prof. Newport could use a little cryptanalysis and a little deduction to determine the key. WIth the algorithm and the key in hand, turning the enciphered journal into a cleartext journal is trivial.
Also worth noting is the places where Wesley decided to use the encryption and where he decided to write in the clear:
He lapsed into shorthand when he wrote about sensitive subjects, such as his disputes with John Wesley over the future direction of Methodism, and his vehement disapproval of his brother’s proposed marriage to Grace Murray.
Clearly, Wesley knew that some personal information should remain personal and private. Some things he journaled were sensitive and secret and needed to stay that way. Often, it’s only important that the information stay encrypted long enough. In 2008, his feelings on his brother’s marriage proposal just aren’t urgent anymore.
Hearing that Charles Wesley had used cryptography gives me more reason to believe that Christians do in fact have historical and theological reasons to be interested in privacy and security. If it was true in the 1788, it’s no less true in 2008.