University of Virginia, Department of Computer Science
CS588: Cryptology - Principles and Applications, Fall 2001

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Challenge 1: Jefferson Wheel Ciphertext

The Jefferson Wheel Challenge was solved!

Jefferson's Letter to Captain Lewis, June 20, 1803

Solved by Geoff Stoker, a student in last year's CS551 course, 30 November 2001.

This email message explains how he solved it. The code he used is available here.

The message was Jefferson's instructions to Captain Lewis for the Expedition to the Pacific. It includes this passage:

Avail yourself of these means to communicate to us at seasonable intervals a copy of your journal, notes & observations of every kind, putting into cipher whatever might do injury if betrayed.

The complete text is available from

Captain Lewis did send several messages back to Jefferson during the expedition, but I don't know if any were actually encrypted using the Jefferson Wheel Cipher. The instructions, obviously, were not, since you can read Jefferson's plaintext handwriting.

Jefferson's Original Description of the Wheel [Archive]

CS 655 University of Virginia
Department of Computer Science
CS 588: Cryptology - Principles and Applications
David Evans