What I learned about Cryptography

In preparing a presentation on cryptography for a graduate class, I was surprised by what I learned.

Cryptography has been used from ancient times through the Industrial Age to the modern day. It's been used for military, diplomatic, criminal, and commercial purposes.

In the simplest and oldest form, Greeks used strips of paper wrapped around sticks of a certain size called a scytale - rhymes with Italy.

Julius Caesar is one of the first known users of the simple letter substitution method. The modern day cousin is ROT13.

If he had anything confidential to say, he wrote it in cipher, that is, by so changing the order of the letters of the alphabet, that not a word could be made out. If anyone wishes to decipher these, and get at their meaning, he must substitute the fourth letter of the alphabet, namely D, for A, and so with the others.
—Suetonius, Life of Julius Caesar

Hiding messages (steganography) is as old as the ancients. An example would be a tattoo on a shaved head. The hair would grow back hiding the tattoo. A modern example is hiding text in the pixels of a digital image.

Charles Babbage is a name taught in every into to computer science class as a pioneer in computing machines. I never knew that he helped the English during the Crimean War by breaking cryptological codes.

Mary "Queen of Scots" was caught when one of her secret codes were broken.

The Voynich Manuscript may have been an elaborate hoax to defraud a king, who had a interest in mysteries like coded messages, out of a large amount of gold.

A mob boss used encrypted messages to give out orders to his lieutenants and was arrested when the police cracked his amateur code.

Cryptography is thousands of years old and is used all around us everyday.

Behind every great man...

I don't normally think about book reviews as a subject for this space but Galileo can be considered an Honorary Codewright. So with that said, here is a review I wrote this past summer...

Over the weekend I finished reading Galileo's Daughter by Dava Sobel. It was a fantastic read. It's more of a biography of the great man but told really well. I was impressed with the historical research from political/military events around Europe to the intrigue of the Catholic church. Even minor things, like getting to hear about his family's financial troubles or the details of printing a book in those times brought enlightenment. I never knew that cloistered nuns in the 17th century had to deal with money to such an extent. There are several things that really come through. The man was as devoted a Catholic as you'd ever meet. The idea that he had gone against it brought him to his knees. In contrast to his faith, he also had a deep desire for the truth and this legendary collision between faith and science, centered upon this one brilliant and pious man, speaks volumes about human nature. What you will not forget though is his relationship with his exquisitely minded (his words) oldest daughter Virginia who took the appropriate name Maria Celeste when she took her vows. Even though his letters to her do not survive, we have a treasure trove of her letters to him that reveal as devoted a daughter as any father could ever want. That she reveres him and dotes on him is even more incredible considering it was all done from within the walls of the San Matteo convent. From the mundane news of her fellow nuns to the huge responsibilities of taking care of Galileo's estate and accounts while he was in Rome facing charges of heresy, she was always there for him as he was for her; ever his confidante, his guardian angel, his supporter, his devoted daughter. The author closes the story with such care and brings the relationship between the great man and his reverent daughter full circle in such a way that, like the motion of the stars he strove most of his life to reveal to the world, the soul of the reader will be forever moved.

This is the short form. I need to write a longer review, hopefully later this week.