British Ciphers during the Revolutionary War
During the American Revolutionary War, a book cipher was used between Frederick Haldimand (Dictionary of Canadian Biography, Wikipedia), Governor of the Province of Quebec (1778-1786), and Sir Henry Clinton, British Commander-in-Chief in North America (1778-1782), based in New York.
Other users include Guy Carleton (Commander-in-Chief after Clinton), James Robertson (Governor of New York (Wikipedia))), General Knyphausen (Wikipedia), and Lord Germain (Secretary of State for the Colonies).
Correspondence in the Archives
Introduction of the Book Cipher
Six Lectures on Cryptology by William F. Friedman (1965) (pdf), p.41-43, tells how the key of an undeciphered ciphertext was identified by an officer in NSA, Captain Edward W. Knepper, USSN. The ciphertext was a letter from 13 September 1781, which consisted of columns of figures in pairs.
|
22.6 .7 .8 .39 .5 .9 .17 |
|
.20 .12 .31 |
| ... |
(The first figure of the pair is omitted when the same figure is repeatedly used. My transcriptions below supply the omitted first figures. The separator can be "." or "-", of which the latter is adopted below. A ruler line delimiting words are omitted below.)
It was obvious that each pair of figures referred to a line number and a letter number in the line in a key text. Then, it was straightforward to decipher this because of repeated use of the same combinations.
22-6 v 22-7 e 22-8 r 22-39 m 22-5 o 22-9 n 22-17 t 22-20 a 22-12 s 22-31 s .... 23-38 w 23-32 i 23-35 l 23-36 l 23-9 s 23-2 a 23-5 i 23-35 l 23-5 i 23-8 n a few days
(The plaintext is in the British and Canadian archives: "Vermont assembly is to meet the 1st Octr. I shall send a large detachment ...." See p.341 (Image 989) at the link below. (I could not find the above ciphertext per se in the archives.))
The correspondence between letters and the line/letter numbers allows partial reconstruction of the key text. The captain realized that the key text was a British Army List and used the date of the message as a clue to identify the book in the Library of Congress.
The key is the front page of A List of the General and Field Officers (1778). (Clearer copies, albeit of different editions, are found on the web: Internet Archive)
Haldimand's correspondence is in the British Library, Additional Manuscripts 21807 and 21808, which are (manually) copied in Public Archives Canada as Haldimand Papers MG21 (Leighton and Matyas (1985), n.30).
The conversion table by Guylaine Pétin referred me to Haldimand Papers: H-1649, in which Image 637 begins "Correspondence with Sir H. Clinton, Sir Guy Carleton, and other officers at New York. 1777-1783, Vol.I, Presented by W. Haldimand , Esq. Jan.1857, Mus. Brit. 21807". Vol.II begins at Image 1969 (corresponding to Add MS 21808). (In the following, the folio numbers are those in these volumes. While Vol.II restarts from f.1, the confusion will be minimum.)
Haldimand started using the cipher in his correspondence with Clinton in December 1778. Two letters in French relate to the introduction of the cipher, but I want historians' advice about their exact nature.
There is an "autograph draft" of a "Letter in French, to Sir Henry Clinton concerning the cypher, dated 23d Novr 1778" (f.34, Image 671; Add MS 21807 f.24).
The writer, presumably Haldimand (Haldimand is known to have corresponded with Clinton in French. See Wilcox, Portrait of a General, p.52, n.3. Some letters below are endorsed in French. Given that Haldimand was born in Yverdon (a French-speaking region in Switzerland) and was baptized François-Louis-Frédéric, his first language seems to have been French.), sent Clinton a cipher in a double envelope using a wafer (oublie) and a seal (cire). The person entrusted with this, ignorant of the content, offered to give Clinton a cipher he had shared with someone else and Haldimand. Haldimand accepted the offer, though unnecessary, lest he would notice the packet he carried contains a cipher.
The first use of the book cipher with the above key is in a letter from Haldimand to Clinton, 16 December 1778 (f.35, Image 672; Add MS 21807, f.26).
The main ciphertext covers the body of the letter "If ... July", accompanied by a ciphertext for "Ha[l]dimand" "to" "Sir Henry Clint[o]n".
The caution "If you receive this letter wel sealed with a wafer" appears to indicate the cipher was conveyed with this first message. It is wondered whether the November draft was not sent, or was sent but did not get through, or involved some other cipher.
The volume also includes "Explanation of the Cypher sent to Sir Henry Clinton in French and English" (f.402-405, Image 1051-1054; Add MS 21807, f.323-326). It not only explains the scheme but also identifies the key text as "Le titre de la liste de l'armee."
I - 4 - 2 h - 11 - 1 a - - 8 v - 22 - 6 e - - 3 c - 20 -16 e - - 7 r - - 15 t - - 1 a - - 5 i - - 14 n - - 25 ...(f.404)
J - 1 - 7 a - - 29 y - - 2 d - 6- 15 e - - 13 s - - 23 i - - 12 n - 6 - 3 t - 2- 1 e - - 3 l - 4 - 1 i - - 2 g - 6 - 1 e - 1 - 4 n - 6 - 3 c - 2 - 6 e - - 5 s - 4 - 3 ...(f.405)
Although this is filed before a letter from October 1781, this may have been the explanation given to Clinton in December 1778. (Chronological ordering is not always observed, as seen in placement of deciphered copies.)
Before the explanation of the book cipher in French is filed another undated letter to Clinton in English (a deciphered copy; f.400, Image 1049), which reports difficulties in communication because of the vigilance of the Americans.
The letter is concluded with "I wait for a vessel to send you a cypher less tedious, and full as safe". The "less tedious" cipher does not seem to refer to the book cipher as might be indicated by the filing order. I think it may refer to code numbers representing whole words, of which the earliest specimen in the volume is Clinton's letter of 22 February 1782 (see below). When code elements are used, words enciphered letter by letter with the book cipher are marked with "x" at the figure pair for the first letter.
My reconstruction of code elements is given below. (Blanks in the reading indicate figure pairs that are used in specimens I examined but could not be identified. Examination of more specimens may allow filling the blanks.)
It can be seen entries with the same second figure have the same initial letter. The highest number for the first figure is 54 for words beginning in S.
While inflectional/derivational endings are occasionally appended to the figure pairs, it appears the figure pairs were often used for inflected forms without such explicitly written endings.
3-1 August? 5-1 attack 7-1 arrived 8-1 9-1 a 10-1 and 11-1 an 15-1 as 17-1 at 18-1 are 21-1 am 30-1 accounts 31-1 about 1-2 by 3-2 been 4-2 6-2 be 2-3 Connecticut 13-3ed communicated 15-3 channel 26-3 command 46-3 combined 3-4 7-4 Detroit 12-4 [days???] 28-4 1-5 England 3-5 excellency 4-5 express 38-5 49-5 exactly 1-6 France 2-6 French 5-6 from 6-6 for 7-6 23-6 fortnight 24-6 | 2-7 general 7-7 15-7 garrison 39-7 1-8 his 3-8 here 8-8 had 9-8 has 18-8 him 21-8 he 22-8ble honorable 41-8 head 2-9 June 3-9 July 20-9 inform(ation) 24-9 instance 25-9 instead 27-9 invade 29-9 in 30-9 I 32-9 it 33-9 is 40-9 important 46-9 just 47-9 intelligence 51-9 induce 2-10 know 7-10 2-11 letter 19-11 large 23-11 learn't 22-12 me 25-12 may? 27-12 minister 29-12 making 37-12 Mr. 42-12 majesty 13-13 new? | 2-14 Ohio 3-14 of 4-14 one 8-14 ordered 13-14 on 17-[1?]4 officers 29-14 opened 33-14 other 34-14 our 1-15 8-15 province(s) 17-15 prisoners 21-15 packet 32-15 peace 41-15 person 42-15 place 49-15 proceedings 1-17 received 51-15's provisions 2-17 returned 7-17 rebels 34-17 regiments 45-17 rout | 1-18 5-18 since 8-18 send 9-18 should 18-18 successfull 23-18 Spaniards 30-18 strong 43-18 seen 48-18 some 51-18 state 54-18 4-19 to 5-19 the 8-19 that 9-19 this 10-19 12-19 troops 13-19 these 22-19 thence 41-19 two 43-19 thousand 46-19 thirteen 3-20 undertake 4-20 upon 6-20 up 6-21 very 4-22 which 5-22 who 6-22 where 8-22 with 9-22 what 10-22 was 11-22 were 17-22 will 18-22 we 20-22 way 41-22 weak 2-24 your 3-24 you 4-24 yet |
Actually, use of code was already observed by Leighton as early as 1985.
f.35 (Image 672) Haldimand to Clinton, Quebec 16 December 1778
4-2 i 5-2 f 2-12 yfq 5-1 o 1-27 u 1-5 r 1-4 e 2-6 c 1-7 i 22-6 v 22-7 e 22-1 t 22-2 h 22-14 i 22-12 t 1-31 l 1-32 e 1-22 t 2-3 e 2-8 e 19-1 w 20-3 e 22-13 l 2-4 s 2-5 e 2-10 a 1-31 l 1-32 e 6-15 d 19-1 w 19-2 i 19-3 t 19-4 h 20-5 a 26-1 w 25-1 a 26-11 f 26-7 e 26-13 r 16-6 y 16-5 o 22-16 u ... 2-15 w 2-16 a 7-6 y 27-9 & ... 8-3 t 19-1 w 11-2 o 26-8 u 26-10 i 26-20 c 26-3 t 25-3 u 25-1 a 25-16 l 25-19 [s] ... 18-10 i 18-17 u 18-18 l 18-29 y [in the margin] 1-23 h 1-29 a 1-37 ? 11-6 d 13-3 i 13-25 m 13-8 a 13-9 n 13-10 d 14-1 t 14-2 o 13-6 s 13-3 i 13-2 r 13-7 h 13-16 e 13-9 n 13-2 r 21-17 y 6-20 c 6-14 l 6-12 i 6-3 n 8-3 t 9-10 n
f.96-99 (Image 734- ) Clinton to Haldimand, New York, 9 September 1779 (decoded f.85-94 (Image 723- ): "I was favored with ...")
There are many errors in counting.
1-7 i 2-15 w 1-27 [a] (-2 error) 2-4 s 1-13 [f] (-1 error) 1-27 [a] (-2 error) 9-15 [v] (-1 error) 1-10 [o] (-1 error) 1-17 [r] (-1 error) 1-4 e 6-15 d
f.120-122 (Image 758- ) New York, Clinton to [Haldimand?], 22 October 1779, decoded p.134- : "I was honored with your letter of the 19th July ..."
1-7 i 2-15 w 1-27 [a] (-2 error) 2-4 s 1-13 [f] (-1 error) 1-27 [a] (-2 error) 9-15 [v] (-1 error) 1-10 [o] (-1 error) 1-17 [r] (-1 error) 1-4 e 6-15 d 2-15 w 1-7 i 2-9 t 5-4 h 16-6 y 1-10 [o] (-1 error) 18-7 [u] (unexplained error) 1-17 [r] (-1 error) 4-1 l 1-4 e 2-99 tt (doubling "9" seems to repeat the letters; see also "44" below) 1-4 e 2-17 r 2-4 s 1-10 [o] (-1 error) 1-13 [f] (-1 error) 2-9 t 1-15 [h] (-1 error) 1-4 e
f.145-147 (Image 783-785) Robertson to [Haldimand?], New York, 23 March 1780, decoded on f.118 (Image 756): "I esteem it requisite to inform ..."
(Robertson was the Governor of New York (Wikipedia)).
1-7 i
1-4 e
4-3 s
4-4 t
1-44 ee
1-6 m
4-2 i
4-4 t
1-5 r
1-4 e
[a dot in a circle]-("q" had to be represented in a special way, as arranged on p.402)
18-17 u
1-7 i
4-3 s
4-2 i
4-4 t
5-5 e
f.148 (Image 786) New York, 29 March 1780, "James Robertson", decoded on f.119: "Dear Sir, on the 18th on this month I left ..."
11-6 d 2-3 e 6-6 a 1-5 r 2-4 s 4-4 [i] (+2 error) 1-5 r 5-1 o 6-3 n 5-3 t 5-4 h 5-5 e 10th (not enciphered) 1-12 o (-1 error) 1-13 f (-1 error) 5-3 t 5-4 h 4-2 i 4-3 s
f.158 (Image 796) New York, Knyphausen to [Haldimand?], 4 May 1780, decoded on f.155: "A frigate is just arrived express"
General Knyphausen (Wikipedia) was with Robertson in New York ("General Robertson, who presents respects, adds that ...").
3-1 a 6-9 [f] (-2 error) 1-5 r 1-7 i 1-20 g 6-6 a 5-3 t 5-5 e 4-2 i 4-3 s 13-11 j 18-17 u 4-3 s 4-4 t 6-6 a 6-5 r 6-5 r 4-2 i 9-15 v (-1 error) 6-13 e 6-15 d
f.176 (Image 819), Knyphausen to Haldimand, New York, 30 May 1780, decoded on p.179: "Charlestown surrendered the 12th instant"
21-1 c 5-4 h 6-6 a 1-5 r 6-7 l 5-5 e 4-3 s 2-1 t 11-2 o 14-3 w 6-3 n
f.184 (Image 827), Clinton to Haldimand, New York, 6 July 1780, decoded on p.186: "I have received your dispatches"
1-7 i 2-2 h 2-16 a 9-16 v 9-6 e 2-7 r 2-3 e 2-6 c 2-5 e 1-7 i 9-16 v 9-17 e 6-15 d
f.226 (Image 870), Clinton to Haldimand, New York, 14 August 1780, decoded on p.225: "Monsieur Terney arrived the ultimate"
(The endorsement "Chiffre du Ch: Clinton du 14me d'Aoust 80" refers to "Chevalier", i.e., Sir Henry Clinton. See the letter of f.34 quoted above.)
1-6 m 1-11 o 1-12 n 2-4 s 4-2 i 5-5 e 18-17 u 11-3 r 17-1 t 17-3 e 17-5 r 17-19 n 17-18 a 17-17 y
f.224-233 (Image 873), Clinton to Haldimand, New York, 9 September 1780, decoded on f.234: "On the 14th of last month I despatched a messenger, by land to your excellency with a letter in cypher ..."
21-1 c 21-17 y 21-4 p 21-12 h 21-13 e 21-15 r
f.242-244 (Image 886), Clinton to [Haldimand?], New York, 2 October 1780 (the day André was executed), duplicate on f.239, decoded on f.245: "General Arnold discovered an intention of giving up the Forts etc. etc. at ("etc. etc. at"[?] is not enciphered) West Point"
6-1 g 6-2 e 6-3 n 6-4 e 6-5 r 6-6 a 6-7 l 15-1 a 6-5 r 6-3 n 11-2 o 6-7 l 18-3 3
f.247 (Image 891) Clinton to Haldimand, New York, 18 October 1780, decoded on p.246: ".... I am concerned for the miscarriage of the Quebec fleet"
.... I am concerned 5-2 f 5-1 o 7-7 r the 1-6 m 1-7 i 1-8 s 9-5 c 9-19 a 9-18 r 9-18 r 9-4 i 7-1 a 9-23 g 9-22 e
f.289 (Image 934) Haldimand to Clinton, Quebec, 7 February 1780, duplicate, decoded on f.290: "Anxious to hear from you & to stand against"
15-3 a 15-2 n 15-19 x 15-11 i 25-15 o 25-3 u 25-2 s 26-3 t 26-12 o 26-4 h 26-7 e 26-19 a 26-13 r 26-11 f 26-13 r 26-17 26-14 m
f.299 (Image 945), Clinton to Haldimand, New York, 8 May 1781, decoded on p.308: "Vermont deserves our vigilant attention."
9-16 V 9-17 e 9-18 r 9-25 m 9-1 o 9-27 n 9-28 t 18-3 d 18-6 e 18-13 s 18-12 e 18-9 r 9-16 v 9-6 e 9-8 s our 9-16 v 9-9 i 9-23 g 9-9 i 9-20 l 9-19 a 9-10 n 9-11 t 9-19 a 9-11 t 9-11 t 9-6 e 9-10 n 9-11 t 9-4 i 9-1 o 9-10 n
f.304, Clinton to Haldimand, New York, 8 May 1781, decoded on p.307: "... Ensign Drum[m]ond of 16th Novr have not reached me"
extract
I received yours of the 7th February, but the letters you mention to have sent me by
9-6 E
9-10 n
9-8 s
9-9 i
9-10 n
9-23 g
11-6 D
11-7 r
18-17 u
1-6 m
1-6 m
1-10 o (-1 error)
1-11 n (-1 error)
18-3 d
of 15th November has not reached me
f.311 (Image 958) New York, Clinton to Haldimand, 31 May 1781 decoded on f.313: "I have received your letters ... "
... 27-1 c 27-2 l 27-3 o 27-4 t 27-5 h 27-6 i 27-7 n 27-8 g &c. for the 6-1 G 6-2 e 6-5 r 1-6 m 6-6 a 6-3 n
f.350 (Image 998)
There are figures on a blank page of a letter from Clinton, 28 September 1781, but these may not be cipher.
f.382 (Image 1030), Clinton to Haldimand, 12 November 1781, decoded on p.385: ".... Of your proclama and"
extract
....
5-1 o
5-2 f
7-6 y
18-14 o
18-17 u
18-9 r
1-3 p
1-5 r
1-11 o
2-6 c
18-18 l
18-1 a
18-4 t
18-10 i
18-14 o
and
f.402 (Image 1051), not dated
A letter in French explaining a cipher and identifies the key text (see above).
f.406 (Image 1056) General Robertson to [Haldimand?], 31 October 1781, decoded extract on f.381: "Sir Henry Clinton with about six thousand men went on board a fleat of 25 sail of the line to try to relieve lord Cornwallis. He was forced to surrender on the 19th the very day our fleet sailed, we have not heard from Sir Henry nor of our fleet...."
extract
Dear Sir -
Thanks for the farrs[?],
your letters, & the great pleasure I
have in having continued in your friendship
2-4 s
4-2 i
2-7 r
2-2 h
2-3 e
1-12 n
1-5 r
7-6 y
f.1 (Image 1070) Circular Letter from Lord Germain, 2 January 1782 (The marginal note by the copyist refers to another copy on p.120 and decode on p.238 but I could not find them. These seem to belong to some other volume.)
2-1 t 2-2 h 2-3 e 4-1 l 16-5 o 16-6 y 16-7 a 16-8 l 16-9 r 16-10 e 18-16 f 18-17 u 16-11 g 16-10 e 16-10 e 4-3 s
f.4 (Image 1073) from Lord Germain, 2 January 1782
I was well pleased to find by a copy of your letters of the 1st October 14-1 t 14-2 o 2-4 s 18-10 i 18-9 r 11-1 h 11-5 e 11-12 n 18-9 r 18-29 y
f.11 (Image 1080) from Clinton, New York, 22 February 1782, decoded on f.8-10: "I think it right to send by express to your excellency the following intelligence which has just been communicated to me by the honorable William Smith Chief Justice of this Province, exactly as it was given to me by him. 'About a fortnight since an intelligent person from Connecticut suggested, that ....'"
This letter uses code elements (see above) for the first time in this volume. The first letter of a word spelled with book cipher elements is marked with "x" before the figure pair. For the first few columns, subsequent letters in such a word are also marked with a small "x", which seems to show that this letter was really one of the first to employ code elements, in which the user had to get accustomed to switching between book cipher elements and code elements. (In my transcription below, all book cipher elements are marked with "x".)
30-9 I x7-3 t x7-4 h x7-11 i x7-12 n x7-10 k 32-9 it 8-13[?] right 4-19 to 8-18 send 1-2 by 4-5 express 4-19 to 2-24 your 3-5 excellency 5-19 the x5-2 f x5-1 o x4-1 l x4-1 l x5-1 o x19-1 w x19-2 i x11-12 n x11-9 g 47-9 intelligence 4-22 which 9-8 has 46-9 just 3-2 been 13-3ed communicated 4-19 to 22-12 me 1-2 by 5-19 the 22-8ble honorable x19-1 w x19-2 i x16-8 l x16-8 l x16-12 i x16-7 a x16-13 m x18-13 s x18-7 m x18-10 i x18-4 t x18-5 h x21-1 c x21-12 h x21-9 i x21-13 e x5-2 f x13-11 i x18-17 u x18-18 [s] x18-4 t x18-10 i x9-5 c x9-6 e 3-14 of 9-19 this 8-15 province 49-5 exactly 15-1 as 32-9 it 10-22 was | x22-4 g x22-14 i x22-6 v x22-7 e x22-9 n 4-19 to 22-12 me 1-2 by 18-8 him 31-1 about 23-6 fortnight 12-4 [days???] 5-18 since 11-1 an x16-12 i x16-15 n x16-16 t x16-8 e x16-8 l x16-8 l x16-12 i x16-11 g x16-14 e x16-15 n x16-16 t 41-15 person 5-6 from 2-3 Connecticut suggested 8-19 that tho' 5-19 the 7-17 rebels x4-4 t x3-1 a x4-1 l x7-10 k x7-5 e x11-6 d 3-14 of 11-1 an 5-1 attack in 5-19 the spring 4-20 upon x18-2 n x18-6 e x19-1 w x2-12 y x11-1 o x11-3 r x7-10 k 21-8 he 8-8 had 30-18 strong suspicions 3-14 of 9-1 a preparation 4-19 to 27-9 invade x21-1 c x18-8 a x18-11 n x18-8 a x18-3 d x18-8 a | 10-1 and yesterday 30-9 I 23-11 learn't 1-2 by 9-1 a direct 15-3 channel 8-19 that 2-7 general x2-4 s x2-6 c x2-2 h x18-17 u x2-12 y x18-18 l x18-6 e x18-9 r x18-18 s x18-1 a x18-10 i x18-3 d 4-19 to one 3-14 of 1-8 his x21-1 c x21-2 o x21-7 n x5-2 f x21-9 i x21-8 d x21-13 e x21-7 n x21-11 t x21-5 s 10-1 and 4-24 yet 34-14 our friend 8-19 that x4-1 l x3-1 a x5-2 f x18-1 a x18-29 y x18-6 e x18-4 t x18-4 t x18-6 e went 4-19 to 1-6 France 4-19 to propose 8-19 that x1-3 p x1-5 r x1-11 o x17-4 j x2-8 e x2-6 c x2-9 t |
10-1 and
8-19 that
they
11-22 were
22-34[?] waiting
4-19 to
2-10 know
5-19 the
x18-9 r
x18-12 e
x18-13 s
x18-17 u
x18-18 l
x18-4 t
5-19 the
following
47-9 intelligence
33-9 is *"is just" is deciphered as "has been" (and "since the above" is added)
46-9 just
1-17 received
1-2 by
another
15-3 channel
19-11 large
x20-8 s
x20-6 t
x20-9 o
x20-15 r
x20-14 e
x20-8 s
3-14 of
51-15's provisions
17-1 at
5-19 the
falls
3-14 of
2-14 Ohio
|
5-19 the Rebel 2-7 general x21-1 c x24-2 l x24-1 a x24-13 r x7-10 k 9-1 a 6-21 very enterprising x18-7 m x18-8 a x18-2 n 33-9 a Virginian[?] 17-1 at x7-10 k x7-18 [a] x7-11 i x7-12 n x18-4 t x18-17 u x2-6 c x7-10 k and is to x22-2 h x22-20 a x22-6 v x22-7 e | 5-19 the 26-3 command 3-14 of 41-19 two 51-18 state 34-17 regiments besides 33-14 other 12-19 troops 8-22 with 31-1 about 4-14 one 43-19 thousand 2-6 French 10-1 and 23-18 Spaniards 8-22 with 13-19 these 5-19 the ensuing x2-4 s x1-3 p x18-9 r x18-10 i x18-11 n x6-1 g | 21-8 he sets 3-14 off 13-14 on 11-1 an Expedition x23-2 a x23-1 g x23-2 a x23-5 i x23-8 n x23-9 s x23-11 t 7-4 Detroit 10-1 and its x20-4 d x20-3 e x21-4 p x20-3 e x20-25 n x18-3 d x18-6 e x18-2 n x2-6 c x4-2 i x5-5 e x4-3 s 1-8 his 45-17 rout 33-9 is down 5-19 the 2-14 Ohio | 4-19 to 5-19 the mouth 3-14 of 5-19 the x19-1 w x3-1 a x1-1 b x3-1 a x2-6 c x2-2 h x2-3 e 22-19 thence 6-20 up 5-19 the same 4-19 to 5-19 the 41-8 head thereof 6-22 where 18-22 we have 9-1 a carrying 42-15 place 5-6 from 22-19 thence 4-19 to 7-4 Detroit 4-19 [to] 51-9 induce 5-19 the 7-17 rebels 4-19 to 3-20 undertake 9-19 this Expedition they have | 1-17 received 30-1 accounts 8-19 that 34-14 our 15-7 garrison 33-9 is 6-21 very 41-22 weak 17-1 at 7-4 Detroit 9-19 this 20-9 information 4-19 to 5-19 the 7-17 rebels 33-9 is 5-6 from 17-15 prisoners 8-19 that have 3-2 been carried 4-19 to 7-4 Detroit 5-22 who have 2-17 returned 48-18 some 3-14 of 5-19 the Rebel 17-[1?]4 officers |
x2-4 s x2-10 a x2-12 y 8-19 that x18-4 t x18-5 h x18-6 e x18-9 r x18-12 e 17-22 will x1-1 b x1-4 e 11-1 an Expedition 2-2 by 5-19 the x15-3 a x15-4 l x15-4 l x15-11 i x15-9 e x15-17 d x9-2 f x9-1 o x9-7 r x9-5 c x9-6 e x9-8 s against x21-1 c x21-6 a x21-7 n x21-6 a x21-8 d x21-6 a | 5-19 the ensuing x2-4 s x18-17 u x18-7 m x18-7 m x18-6 e x18-9 r and 32-9 it 33-9 is x18-1 a x18-13 s x18-13 s x18-6 e x18-9 r x18-4 t x18-6 e x18-3 d 8-19 that 5-19 the Rebels x22-2 h x22-20 a x22-6 v x22-7 e x18-5 a x6-1 g x6-1 g x18-9 r x18-6 e x18-6 e x18-3 d 4-19 to | x22-4 g x22-14 i x22-6 v x22-7 e x21-1 c x21-6 a x21-7 n x21-6 a x21-8 d x21-6 a 4-19 to 5-19 the 2-6 French* the 46-3 combined x9-2 f x9-1 o x9-7 r x9-5 c x9-6 e x9-8 s 3-14 of 5-19 the 2-6 French 10-1 and Rebels should x1-1 b x1-4 e 18-18 successfull | x18-6 e x18-2 n x18-14 o x18-17 u x11-9 g x11-1 h 4-19 to [re]duce *-9 it *-19 that this *-5 engagement *-2 by 5-19 the Rebels 4-19 to 5-19 the 2-5[?] French 33-9 is asserted 1-2 by x18-3 s x18-14 o x18-7 m x18-6 e 5-22 who have 43-18 seen 5-19 the | x3-1 a x16-11 g x18-9 r x18-6 e x18-6 e x18-7 m x18-6 e x18-2 n x18-4 t 13-14 on 5-19 the 49-15 proceedings 3-14 of Congress 9-19 this x19-1 w x19-2 i x18-2 n x18-4 t x18-6 e x18-9 r HC/ |
f.18A (Image 1090) Clinton to Haldimand, New York, 10 March 1782, decoded on p.19-20: "It was scarcely to be expected that the January mail could contain powers adequate to the accomplishment of the "
(When code elements are not used, marking book cipher elements with "x" is not necessary.)
It was scarcely to be expected that the 17-4 i 18-8 a 18-2 n 18-17 u 18-8 a 18-9 r 18-29 y 18-7 m 18-8 a 18-10 i 18-18 l 2-6 c 18-14 o 18-17 u 18-18 l 18-3 d
f.31A (Image 1107) postscript of Carleton to Haldimand, 21 May 1782, deciphered on the same sheet
1-15 t 1-16 h 1-17 e 1-1 b 1-4 e 1-29 a 1-5 r 1-4 e 1-5 r 1-21 h 1-29 a 1-9 s 24-13 r 24-12 e 24-11 c 24-6 e 24-10 i 22-6 v 22-7 e 6-15 d 7-3 t 7-4 h 7-11 i 7-7 r 7-3 t 7-6 y 22-4 g 22-16 u 22-14 i 22-19 n 22-18 e 22-20 a 22-12 s
f.49 (Image 1125) Carleton to Haldimand, 22 July 1782 *A deciphered letter from the same date is at p.50-51 but does not seem to match.
4-24 yet 30-9 I 25-12 may? 20-9 inform 3-24 you 8-19 that 10-19 t- 18-1 are 17-1 at 1-15 p- x23-5 i x23-8 n x23-18 d x23-26 i x23-41 c x23-2 a x23-11 t x23-5 i x23-7 o x23-8 n x23-9 s 3-14 of x11-1 h x11-2 o x11-4 s x18-4 t x18-10 i x18-18 l x18-12 e 28-4 d- x16-34 p x16-5 o x16-12 i x16-15 n x16-16 t x16-41 i x16-42 [n] x16-40 g 38-5 e- 17-1 at 2-24 your 8-15 provinces 10-1 and x14-10 n x14-16 e x14-12 w 7-6 f- 8-1 a- 7-7 g- 7-10 k- 4-2 b- 30-9 I 21-1 am x16-30 d x16-22 i x16-35 s x16-34 p x16-5 o x16-35 s x16-3 e x16-30 d 4-19 to x7-3 t x7-14 h x7-11 i x7-12 n x7-10 k .... 5-19 the x13-1 b x13-26 e x13-8 a x13-12 r x13-26 e x13-12 r 9-8 has 1-17 received 24-6 f- 39-7 g-
f.65A (Image 1142), Carleton to Haldimand, 3 August 1782, decoded on p.66-67: "I have received your excellency's letter of the 22[n]d June, and am to inform you that"
54-18 s- 3-1 August? 3d 3[0]-9 I 9-8 have 1-17 received 2-24 your 3-5 excellency['s] 2-11 letter 3-14 of 5-19 the 22d 2-9 June 10-1 and 21-1 am 4-19 to 20-9 inform 3-24 you 8-19 that 9-1 a 21-15 packet 7-1 arrived 3-8 here 5-6 from 1-5 England 13-14 on 31r 31st 3-9 July 1-2 by 4-22 which 18-22 we 1-17 received 5-19 the 6-21 very | 40-9 important 20-9 information 8-19 that con fer ences 18-1 are 29-14 opened 17-1 at x18-27 p x18-28 a x18-9 r x18-10 i x18-13 s 6-6 for 9-1 a 2-7 general 32-15 peace 10-1 and 8-19 that 4-19 to re move 9-22 what 9-8 has 3-2 been | x18-13 s x18-17 u x18-27 p x18-27 p x18-14 o x18-13 s x18-12 e x18-3 d 4-19 to 6-2 be 5-19 the princi pal x23-22 o x23-20 b x23-9 s x23-11 t x23-10 a x23-41 c x23-36 l x23-42 e 29-9 in 5-19 the 20-22 way 3-14 of 32-15 peace 1-8 his 42-12 majesty 9-8 has 8-14 ordered 1-8 his 27-12 minister 4-19 to x20-4 d | x20-14 i x20-15 r x20-13 e x20-16 c x20-11 t 37-12 Mr. x9-23 g x9-18 r x9-17 e x9-10 n x9-16 v x9-9 i x9-20 l x9-20 l x9-22 e 5-22 who 33-9 is in vested 8-22 with x18-16 f x18-17 u x18-18 l x18-19 l x[30]-1 p x[30]-9 o x[30]-44 w x[30]-6 e x[30]-10 r x[30]-22 s | 8-19 that 5-19 the x20-14 i x20-25 n x20-4 d x20-7 e x21-4 p x21-13 e x21-7 n x21-8 d x21-13 e x21-7 n x21-1 c x21-17 y 3-14 of 5-19 the 46-19 13 8-15 provinces 9-18 should 6-2 be pro posed 29-9 in 5-19 the 1st 24-9 instance 25-9 instead 3-14 of 29-12 making 32-9 it 9-1 a |
f.93 (Image 1174) Carleton to [Haldimand?], 9 September 1782
Duplicate 13-13 new? x21-17 y x21-2 o x21-3 r x20-36 k 6th 1-18 s- 54-18 s- ...
f.123 (Image 1205) Carleton to [Haldimand?], 25 September 1782, another copy on f.126-128 (Image 1208), decoded on f.102 (Image 1183)
3-4 d-? x16-31 c x16-32 o x16-15 n x16-40 g x16-20 r x16-3 e x16-35 s x16-35 s 10-1 and 5-19 the x16-34 p x16-3 e x16-15 n x16-35 s x16-27 y x16-8 l x9-16 v x9-19 a x9-27 n x9-24 i x9-19 a
Haldimand's book cipher above is used not only in correspondence between Quebec and New York but also in letters from Lord Germain in January 1782 (vol.II, f.1, f.4). Assuming those letters were indeed put into cipher by Lord Germain (or his secretary) rather than re-enciphered for circulation in North America, it is wondered whether there was no cipher to protect trans-Atlantic correspondence before Haldimand's proposal in 1778.
It is understandable that Friedman was amazed (p.37) at the statement in a 1959 book that Thomas Gage had no cipher as of 1775.
One is reminded of a seemingly ad hoc grille cipher Clinton used with General Burgoyne during the latter's fatal campaign (see another article).
Of course, Britain had been employing diplomatic ciphers for a long time. They already had more than a thousand entries as of 1700 (see another article). According to Kahn (p.173-174), English diplomatic ciphers were prepared by the Deciphering Branch, experts in cryptanalysis, and generally had four-digit code groups and numerous homophones. As examples, I may give Add MS 32256 f.196 (DECODE R9202), f.122 (R9186), f.70 (R9156). I wonder whether it could be that governors in American colonies and the Commander-in-Chief were not given diplomatic ciphers.
S. Tomokiyo (2018-2024), "Diplomatic Codes after the Glorious Revolution and Use of Printed Templates" (Cryptiana)
DECODE:
Héder, M ; Megyesi, B. The DECODE Database of Historical Ciphers and Keys: Version 2. In: Dahlke, C; Megyesi, B (eds.) Proceedings of the 5th International Conference on Historical Cryptology HistoCrypt 2022. Linkoping, Sweden : LiU E-Press (2022) pp. 111-114. , 4 p. [pdf]
Megyesi Beáta, Esslinger Bernhard, Fornés Alicia, Kopal Nils, Láng Benedek, Lasry George, Leeuw Karl de, Pettersson Eva, Wacker Arno, Waldispühl Michelle. Decryption of historical manuscripts: the DECRYPT project. CRYPTOLOGIA 44 : 6 pp. 545-559. , 15 p. (2020) [link]
Megyesi, B., Blomqvist, N., and Pettersson, E. (2019) The DECODE Database: Collection of Historical Ciphers and Keys. In Proceedings of the 2nd International Conference on Historical Cryptology. HistoCrypt 2019, June 23-25, 2019, Mons, Belgium. NEALT Proceedings Series 37, Linköping Electronic Press. [pdf]
As for the French, it is known that code was used around 1780 by General Rochambeau and Admiral de Barras (see another article), Luzerne, minister to the United States, (see another article), and a governor of a Caribbean colony (see Pierrot et al.). It may be interesting to see whether and what ciphers were used by their British counterparts such as Rodney, Carlisle, the governor of Jamaica (Wikipedia), or Carleton as Governor in Canada (Carleton's correspondence with Haldimand in the above are in his capacity as Commander-in-Chief succeeding Clinton).
S. Tomokiyo (2018), "French Code between General Rochambeau and Admiral de Barras (1781)" (Cryptiana)
S. Tomokiyo (2015-2017), "Code Switching in French Diplomatic Correspondence and Intercepted Letter of Barbé-Marbois (1782)" (Cryptiana), supplemented by my blogpost (2024).
Pierrot, Chaline, Damoiseau-Malraux, Mekhail, Perret (2025), "A Caribbean Directory-based Encryption during the American War of Independence" (HistoCrypt 2025) quoted in my blogpost.
British military commanders such as General Cornwallis are known to have used simple substitution ciphers, but Carnwallis introduced in January 1781 switching of the key in the middle of a letter, which was also used with Clinton.
Lieutenant Colonel Balfour also used a book cipher for indicating words by page-column-line combinations.
S. Tomokiyo (2009-2010), "Cornwallis' Ciphers" (Cryptiana)
Difficulty in communication between Canada and New York is apparent from the letters to/from Haldimand. Communication by sea was safer but vessels were not always available. So letters were sent not only in duplicate, but also in triplicate or even quadruplicate. For example, vol.II, f.8 (Image 1077) is "Quadruplicate of letter sent in Cypher over land".
The following shows a bearer of a secret letter was also given a harmless letter to show when captured.