Thomas Jefferson Papers
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I. Draft Cipher Table, [April 1803?]

I. Draft Cipher Table

[April 1803?]

The man whose mind on virtue bent
ujh qft epxbp yvas dd maknpa zcmu
the equivalent of the 1st. lre is taken from the 1st. col.
of the 2d from the 2d
of the 3d from the 3d.
and so on to the 26th. and then begin again
with the 1st. 2d. &c.

or instead of using them in the regular numerical order, have a key word, suppose ‘artichoke’ and finding the letter to be cyphered [t], in the 1st. vertical column, seek it’s equivalent in the column <under> over a1 in the last horizontal line &c so on as follows

t in the 1st. vertical over a in the last horizontal, which is u
h r z
e t y
m i v
a c d
n h v
I a m a t t h e h e a d o f t h e M i s s o u r i.
a r t i c h o k e a r t i c h o k e a r t i c h
j s f j w a w p m f s x x i a w p r j j l x x z
a l l w e l l, a n d t h e I n d i a n s s o f a r, f r i e n d l y
o k e a r t i c h o k e a r t i c h o k e a r t i c h o k e a r t
p w q x w e u d v s d m f & g m l i b e x p x u & i z x p s e e r

then copy fair thus.


MS (DLC: TJ Papers, 128:22136); undated; entirely in TJ’s hand, including brackets.

then copy fair thus: eliminating the spaces between the words of the encoded message made it more difficult for someone to break the cipher (Kahn, Codebreakers, 149–50). When TJ matched the text of his demonstration message to his key word “artichoke,” he overlooked the final letter of the word “Missouri.” Correcting the mistake would have required redoing one step, and perhaps both steps, of the encryption process for more than half the message. Instead, he omitted that letter from his encipherment.

1TJ here canceled “to wit t the next letter h under the 17th. vertical column r (it is y) the next e under t (it is x) the next m under i (it is u) the next a under c (it is e) the next n under h (it is v) &c,” followed on a new line by “the man,” canceled, and “in the bottom line viz u,” also canceled.

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