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LECTURE I SECTION 2 

Revolutionary War Period - Systems used by Americans and by British: 

Ciphers 

Americans: 

a Simple monoalphabetic substitution 

b Monoa.1phabetic with variants by use 

of long key sentence ala Franklin. 

c. Vigenere with repeating key 

a. Dictionaries 

b. Keybook using words 

c. Syllabaries 

Secret inks 

Grilles 

Codes 

British: 

a Monoalphabetic substitution 

b. Vigenere with repeating key 

c Grilles 

a. Dictionaries 

1 Entick's 

2 Bailey's 

b. Small alphabetic l-pa.rt codes 

of 6SS-7SS items and code names 

c Ordinary book such as Blackstone - page, line, no of words in line 

In addition, code or conventional words used to represent name of persons and 

places. British used code names. In Clinton Pa.pers following are found: 

American Generals - Apostles (Washington = James 

(Sullivan = Matthew 

Philadelphia 

Detroit 

Delaware 

Susquehanna 

Indians 

Congress 

- Jerusalem 

- Alexandria 

- Red Sea - Jordan 

- Pharisees 

- Synagogue 

@'pp roved for Release by NSA on 09-13-2013 pursuantto E .0. 1352a 
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6 31 

Jefferson Syllabary 

(Encoding) (enciphering) 

encrypting 

Ty:pical of the small codes and syllabaries used at the time. 

6 3 

Tii'e' syllabary used by Thomas Jefferson (Extract from decoding section). 

(That all 'round genius also may be regarded as being the first American 

inventor of cryptographic devices -- as will be discussed later.) 

257 

The' New Spelling Dictionary by Rev John Entick, London, 1782 

232 

Bri"tish Cipher Message using title page of the Army List Message dated 

13 September 1781. 

Applies to 232.1 

LINE 22 

THE GOVERNORS LIEUTENANT GOVERNORS & C OF HIS 

1 2 3 4 5 6 7 8 9 lf/J 12 13 15 17 19 21 23 25 27 29 31 32 33 34 36 38 

11 14 16 18 20 22 24 26 28 3f/J 35 37 

MAJESTY'S 

394f/J41424~4445 46 

Line 23 

G A R R I S 0 N S A T H 0 M E A N D A B R 0 A D, W I T H T H E I R A L L 0 W -

1 2 3 4 5 6 7 8 9 lf/J 12 14 16 18 2f/J 22 2!J. 25 27 29 31 33 35 37 

11 13 15 17 19 21 23 26 28 3f/J 32 34 36 

ANCES 

38 3SIS 414243 

"No 611 

22. 

6 7 8 39 5 8 17 2f/J 12 31 26 39 23 2f/J 35 22 45 14 12 22 10 39 26 15 17. 

VE$. MONT AS SEM8 :BL8 Y ISTOMEET 

orf ri 

..:! ..:! 

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232.1 

The key for the preceding message. (Finding the key after solution) 

Before showing the next slides explain about British crypta.nalysts working 

on American ciphers 

243 

Frankl.in (Dumas) Cipher-Key Text 17fll6-179fll 

244 

Franklin (Dumas) Cipher-Encipher Table. 

Beale Papers. 

Benedict Arnold - "James Moore, Edward Fox, Gustavus" MaJor Andre - 11 Joseph 

Andrews, John Anderson". 

Arnold, disgruntled with inJustices of Congress, starts off anonymous 

correspondence, giving information showing he is well-pl.aced. Arnold gets 

command of West Point They used secret inks, Bailey's dictionary, word cipher 

witb words out of Blackstone and songbooks, grilles, slips of paper enclosed in 

specially constructed hollow bullets. Andre captured September 1786, writes out 

full confession and was banged. Arnold barely escaped to British lines (peculiar 

part of Arnold's treason) 

One of the cipher letters sent by Benedict Arnold to Sir Henry Clinton. 

15 July 178". 

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"If I point out a plan of cooperation by which S(ir) H(enry) (Clinton) 

shall possess himself' of West Point, the garrison, etc. etc., twenty 

thousand pounds Ster1ing I think will be a cheap purchase f'or an 

object of so much importance." 

(FULJ. text - see typewritten sheet accompanying plate 6 5) 

6 5 

Plain text of' the preceding message. 

6.6 

Treason against Washington. Arnold lays a trap for Washington. 

67 

Another example of Benedict Arnold's ciphers. 

68 

.Arnold's Treasonable Cow Letter. 

6 9 

Example of a. grille used by British 

231 

LOVELL, James • 

Congress• cipher expert who managed to decipher nearly all, of not all, of 

British code messages intercepted by the .Americans. 

********* 

To Gen. Greene, cy to Washington) 

Philadelphia Sept. 21, 1781'1 

You once sent some papers to Congress which no one a.bout you could decypher 

Should such be the case with some you ba.ve late1y forwarded I presume that the 

result of my pains, herewith sent, will be useful to you I took the papers out 

of Congress, and I do not think. it necessary to let it be known here what my 

success has been in the attempt For it appears to me that the Enemy make only 

such changes in their Cypher when they meet with misfortune, (as makes a difference 

in position on1y to the same alphabet) and therefore if no talk of Discovery is 

made by me here or by your FaI11J.ly you may be in cha.nee to draw Benefit this 

C8.IllIJB.ign from m.y last Night's va.tching. 

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I am Sir with much respect. 

Your Friend, 

JAMF.8 LOVELL 

Tell about next great l.andma.rk--Egyptian Hieroglyphics and Poe. 

But British crypta.nalysts also were at work on American ciphers 

Tell about collection of Clinton Papers at Clements Library, U of Michigan 

Tell about how a.n operation went awry because of incorrect solution by British 

Army Cryptana.lysts (amateur) with British Army in America. 

Tell about the British Agent who was illiterate. 

And about Ellis history. "The Secret Post Office and Office of Decipherer." 

249' 

Eii'Ciphered resolution of the Revolutionary Congress of the U.S , 8 February 1782 

6.l!a 

Interest in cryptology in Europe. 

Frontispiece of Dlandol. Contre - Espion 1793. 

Breadboard model. of WAC or WAVE Cryptographic Officer. 

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