© 2008 by Donald E. Pusch. Some rights reserved. This work is licensed under the Creative Commons Attribution-Noncommercial-NoDerivative Works 3.0 United States License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/3.0/us/ orsend a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.

[This article was originally published in Louisiana History, the quarterly publicationof the Louisiana Historical Association (www.lahistory.org), vol. 49:463–80.]

Kerlérec's Cipher:The Code Book ofLouisiana's LastFrench Governor

By D O N A L D E. P U S C H

Louis Billouart de Kervaségan, chevalier de Kerlérec, was gov-ernor of French Louisiana from April 1752 to February 1763.During his tenure, Kerlérec sent several hundred dispatches tohis superiors in France, particularly the Minister of the Marine,who at the time had broad administrative control over colonialaffairs and was Kerlérec's primary link to the court of Louis XV.Many of these dispatches—some in code—have survived and arepart of the French Archives Nationales series Colonies C13a,Correspondance à l'arrivée en provenance de la Louisiane, heldtoday at the Centre des Archives d'Outre-Mer, Aix-en-Provence.1

During Kerlérec's term as governor, colonial affairs were heavi-ly influenced by the Seven Years' War (1756-63) and its NorthAmerican component, the French and Indian War (1754-63), andmuch of the governor's correspondence to the minister dealt withmatters related to colonial defense. Because of the sensitivity ofsuch matters and the danger of interception by the English,

The author is a retired lieutenant colonel, USAF, and former avionics integra-tion manager for the Space Shuttle Orbiter secure communications system. Hewould like to thank colleague Pierre Mommessin for his many helpful suggestionsduring the preparation of this article.1All references to documents in the Archives Nationales, Colonies C13a series

are to the 1970 Library of Congress microfilm edition, referred to as the LouisianaColonial Records Project (LCRP) and hereinafter cited as AN, C13a with registerand folio number followed by LCRP reel number.

2

packets of official correspondence were, where possible, entrustedto the captains of departing French vessels. When this was notpossible, dispatches were placed in the care of trusted passengers,often military officers returning to France.2 These couriers hadstanding orders to throw the packets into the sea should theirships come into imminent danger of capture.3

For ships bearing French colors during this era, the peril ofcapture on the high seas was especially high. Between 1757 and1762, the Marine Royale lost to the English some fifty-six of herships-of-line and light frigates; almost three fourths of these ves-sels were captured intact. Losses among the Marine Royale'sheavy supply ships (flûtes, gabarres, and senaux) and freightedtransports were at least as severe; and, owing to their light de-fenses, the great majority of those lost were captured intact.4 Onthe circuit to and from Louisiana, significant captures includedthose of the Aimable Marthe, Marguerite, Trois Maries, andFortuné in 1756; the Marquis de Conflans, Concorde, and BienAcquis in 1757; and the Victoire in 1758.5

Sensitive pieces of correspondence, especially those that couldnot be sent on ships of the king, were sometimes given the addedprotection of full or partial encryption, that is, the conversion oftheir original text into numerical cipher. Because encoding anddecoding were time-consuming tasks, the use of cipher was re-served primarily for correspondence dealing with diplomatic ormilitary matters. In the case of Kerlérec's dispatches, cipher wasmost often used to protect information dealing with Louisiana'sdefenses, the shortage of provisions and manufactured goods—especially those needed as gifts for the Indians—or with militaryintelligence related to the English or their Indian allies. In a few

2In cases where returning French ships were not available, Kerlérec is knownto have sent dispatches by way of Spain, Holland, and Denmark or through otherFrench colonies such as Saint Domingue. Kerlérec to Minister, New Orleans,December 8, 1759. AN, C13a 41, folio 147-49vo, LCRP reel 48.3The officer Duplessis, captured by an English corsair soon after sailing from

New Orleans on the brigantine Félicité, mentions this order—and the execution ofit—in a report to the Minister of the Marine made soon after his release.Duplessis to Minister, Havana, January 25, 1757. AN, C13a 39, folios 302-03,LCRP reel 46.4These statistics are based on data presented in Alain Demerliac, La Marine de

Louis XV: Nomenclature des navires français de 1715 à 1774 (Nice, 1995).5Prize Papers, National Archives of the UK, Public Record Office, High Court of

Admiralty (HCA 32); microfilm, Library and Archives Canada.

3

instances, cipher was also used to cloak Kerlérec's reports on thealleged misdeeds of other colonial officials and military officers.

In their original form, Kerlérec's encoded dispatches pose an in-teresting problem: Aside from an occasional line or paragraph ofreadable text, their content appears simply as rows of numbersseparated into groups of one, two, or three digits. An example ofthis can be seen in Kerlérec's dispatch no. 215 to the Minister ofthe Marine, the first several lines of which are reproduced below.6

A portion of Kerlérec's encoded dispatch no. 215

When a letter like this reached France, it was processed by acipher clerk at the Ministry of the Marine and converted intolines of readable text, which were then added as interlineationson the original document. Most of Kerlérec's encoded dispatchesbear such annotations.

Encoding or decoding a dispatch required the use of a code bookcontaining the cipher. The one used by Kerlérec has not sur-vived; however, clues as to what it contained can be found bycarefully examining examples of the governor's encoded dispatch-es. For this article, the author analyzed thirty-three such dis-patches, all that could be found in the Colonies' C13a series andelsewhere, and from that analysis was able to recreate most of

6Kerlérec to Minister, New Orleans, September 17, 1759. AN, C13a 41, folio111-11vo, LCRP reel 48.

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Kerlérec's code book.7 This was then reapplied to the encodeddispatches to produce the author's own decoded versions of theoriginals.8 A listing of the dispatches used in this analysis isshown in Table 1.

To understand the encoding system used in the Kerlérec dis-patches, it is helpful to consider a few basic concepts of cryptog-raphy, the first involving a simple system of substitution. Forexample, if one wanted to encode the message, "Les Anglaisviennent," one scheme might be to assign every letter of the al-phabet a number: A = 1, B = 2, C = 3, etc. Through this scheme,the original "plaintext" message could be converted into an en-coded message containing only code numbers, referred to as"ciphertext" or "codetext."

L-E-S A-N-G-L-A-I-S V-I-E-N-N-E-N-T

12-5-19 1-14-7-12-1-9-19 22-9-5-14-14-5-14-20

The specific assignment of numbers to letters is referred to asthe "cipher code." To enhance the security of such a scheme, thecipher code could be changed from time to time, so long as boththe sender and the receiver used identical code books.

The science—some would say art—of "cracking" such codes isreferred to as "cryptanalysis." As one might suspect, a simplecoding scheme such as that given in the example would be highlyvulnerable to cryptanalysis. It is known, for example, that in athousand words of typical French text of the type appearing inthe Kerlérec dispatches, the letter e (diacritics ignored) will occurapproximately 805 times; the letter a, 326 times and so on for theentire alphabet.9 Thus, given enough ciphertext, one could usefrequency analysis of the code numbers to decipher many of theletter-number pairs that make up the cipher code. Other charac-teristics of the language can also aid the cryptanalyst; for exam-

7One dispatch, no. 144, which was also included in the analysis, was found inManuscrit no. 31 du catalogue de La Roncière, folio 299-300, Bibliothèque du portde Brest, now held at the Archives Nationales. LCRP reel 1.8The author is indebted to colleague C. David Lodge for development of the

software filter used in the decoding process.9These statistics are based on the author's own analysis of documents from the

AN, C13a series, the sample set consisting of 10,276 words.

5

ple, in English as well as in French, the letter q will almost invar-iably be followed by the letter u.

The coding scheme used in Kerlérec's dispatches was consider-ably more complex than the scheme used in the example; howev-er, its basic structure was fairly easy to determine, as similarschemes (with different cipher codes) were in use at the sametime by French officials in Canada and had been used a decadeearlier in Louisiana by Kerlérec's predecessor, Pierre François deRigaud, marquis de Vaudreuil.10

The scheme used in all of Kerlérec's encoded dispatches wasfound to be of a type known as a two-part nomenclator, a systeminvented by Antoine Rossignol, cryptographer to the court of Lou-is XIV. According to traditional accounts, one version ofRossignol's encoding scheme was lost to historians until the latterpart of the nineteenth century, when Étienne Bazeries, a memberof the French army's cryptographic service, managed to crack thecode, illuminating a number of the Sun King's previously unread-able documents.11

In the particular two-part nomenclator used in the Kerlérecdispatches, code numbers were assigned to individual letters,word fragments, or entire words of plaintext, for example:12

bâtiment .......293 s ...........49 or 207être................147 secours............ 81Hollande .......459 fi.................... 570pas...................20 u.................... 258présent............68 votre ............. 278

10Code tables created in 1757 for Vaudreuil, then governor-general of NewFrance, and in 1758 for the Marquis de Montcalm are in AN, C11e 10, folio 285-90vo (Centre des Archives d'Outre-Mer), microfilm, Library and Archives Canada,reel F-408. Code tables created in 1742 for Vaudreuil, then governor of Louisiana,are in Maurepas to Vaudreuil, October 22, 1742, Vaudreuil Papers, Loudoun Col-lection, Huntington Library, Art Collection, and Botanical Gardens, San Marino,California), microfilm. These latter code tables fell into the hands of the Englishin 1755 when the sixty-four-gun warship Alcide was captured. Bill Barron, TheVaudreuil Papers: A Calendar and Index of the Personal and Private Records ofPierre de Rigaud de Vaudreuil, Royal Governor of the French Province of Louisi-ana, 1743-1753 (New Orleans, 1975), xi.11Simon Singh, The Code Book: The Science of Secrecy from Ancient Egypt to

Quantum Cryptography (London, 1999), 55-8.12In the two-part nomenclator system, the code elements need not be numbers.

Letters or a combination of letters and numbers could also be used. The code ele-ments used in Kerlérec's correspondence were always numbers.

6

Coding and decoding documents each requires a separate table:The first—the table à chiffrer—is an alphabetically ordered list ofthe plaintext elements (the letters, word fragments, or wholewords) shown with their code-number counterparts (the one-,two-, or three-digit numbers). The second—the table àdéchiffrer—contains all of the same data but is sorted on the codenumbers. As the names imply, the first table is used for encod-ing; the second, for decoding.

Determining the exact cipher code used by Kerlérec could bequite difficult were it not for the fact that plaintext versions—decoded at the Ministry of the Marine—exist for most of the gov-ernor's encoded dispatches from the Colonies C13a series. Eachsuch dispatch provides what is essentially a Rosetta Stone for thecryptanalyst, offering up bits and pieces of the cipher code for col-lection into the recreated code book. Of the thirty-three encodeddispatches analyzed by the author, plaintext versions exist forthirty, and these could be used to support recreation of the codebook. It was then possible to use the code book to verify the de-coding performed by the ministry and to decode the three dis-patches for which no plaintext versions are extant.13

Kerlérec's cipher contained 700 pairs of code numbers and theircorresponding plaintext letters, word fragments, whole words, ornulls, the latter arising from the existence of code numbers thathad no corresponding plaintext.14 The elements of the code iden-tified by the author—a total of 547—are displayed in Table 2 atthe end of this article in the form of a table à déchiffrer (decodingtable). To find the 153 missing code pairs would simply requirethe examination of more coded, annotated documents, if suchcould be found.

In addition to the basic protection afforded by encoding, therewere other useful security features of Kerlérec's two-partnomenclator. First, to confound frequency analysis, some of themore commonly used letters of the alphabet could be encoded in

13The dispatches that contain code for which no corresponding plaintext existsare nos. 206 (Kerlérec to Minister, New Orleans, July 3, 1759, AN, C13a 41, folio81-82), 207 (Kerlérec to Minister, New Orleans, July 13, 1759, AN, C13a 41, folio87-98vo), and 215 (Kerlérec to Minister, New Orleans, September 17, 1759, AN,C13a 41, folio 111-11vo).14Vaudreuil's 1742 code tables cited at note 10 provided for fifteen such null

code numbers.

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two ways. The letter s, for example, could be encoded as either 49or 207; the letter a, as either 114 or 366. Altogether, double codeswere available for nine letters: a, c, d, e, l, n, o, r, and s. A secondsecurity feature permitted whole words to be encoded in differentways. For example, the word particulier could be represented bya single code number (124), or it could be broken into fragments(parti-cu-li-er) and each fragment encoded (568.208.260.495). Athird feature had to do with the existence of null code numbers.Having no corresponding plaintext, these nulls could be insertedin the encoded document at random locations, providing falseclues to the would-be code breaker. Finally, spaces betweenwords were not coded and there was no separate coding for capi-tal letters, punctuation, or diacritics, making difficult the task ofpicking out individual letters, words, phrases, or sentences.

The reason why this particular scheme was used arises from avery practical consideration: In general, the selection of an en-coding system is a compromise between ease of use and security,and the two-part nomenclator is a fairly balanced compromise.15

It is easy to use, requiring only a simple look-up in the table àchiffrer (for encoding) or the table à déchiffrer (for decoding). Al-so, a single error made during encoding would result in the cor-ruption of only one letter, word fragment, or word in the decodeddocument, something that was not the case with other, morecomplex, encoding schemes.16 The two-part nomenclator couldalso be quite secure provided that occasional changes were madeto the cipher code and full advantage was taken of the varioussecurity features inherent in the system.

In practice, however, it was found that Kerlérec's two-partnomenclator was not always used to its best advantage. First, itwas discovered that all of the encoded dispatches examined inthis study were encrypted using the same cipher code. This was aserious weakness. If, in 1755, the English had gained access toeven a few plaintext versions of the governor's encoded docu-ments, the cipher could have been broken and any such document

15Much more secure systems than the two-part nomenclator existed, for exam-ple, the polyalphabetic substitution systems of Blaise de Vigenère introduced ahundred years earlier. Their use, however, was much more tedious and time-consuming. David Kahn, The Codebreakers: The Story of Secret Writing, rev. ed.(New York, 1996), 146-50.16In systems such as Vigenère's, a small error made during encoding could re-

sult in total corruption of the document during decoding. Ibid.

8

intercepted through 1762 would have been compromised.17 Whythe cipher code was not changed during a period of over sevenyears remains a mystery. Perhaps creating, distributing, andadministering new code tables was simply too much of an admin-istrative burden for the Ministry of the Marine.

A second, very serious, weakness had to do with the manner inwhich Kerlérec's cipher clerk used the code book to construct theencoded dispatches. As mentioned previously, certain letters ofthe alphabet could be represented by two different code numbers.The idea was to alternate between the two numbers so as to maskthe frequency of occurrence of the corresponding letters. In prac-tice, the cipher clerk almost always used both code numbers to-gether, one atop the other. This is why, in the dispatch extractshown at the beginning of this article, one finds the code number178 atop the code number 660 (representing the letter e), 114atop 366 (representing the letter a), 49 atop 207 (representing theletter s), and 180 atop 230 (representing the letter r). Apparent-ly, when the cipher clerk looked up these letters in the table àchiffrer and found two numbers listed, he simple wrote down bothof them and in this way unwittingly nullified the intent of thissecurity feature. Also, although it is strongly suspected that nullcode elements were included in Kerlérec's code book, none wasused in any of the encoded documents examined in this study.

Poor security practices were not limited to the encryption pro-cess. At the ministry, when an encoded dispatch was receivedand decrypted, the resulting plaintext was annotated directly on-to the original ciphertext version, and evidence suggests thatsuch parallel texts were then circulation within the ministry.18

For an enemy, having access to these parallel texts would havebeen the next best thing to having access to the code book. Amore secure practice would have been to decode each dispatchinto a separate document and then to destroy or separately ar-chive the encoded version.

17The author was able to recover about 45 percent of Kerlérec's cipher codethrough the analysis of just one, six-page document.18Several of Kerlérec's encoded dispatches were circulated to Commissaire de la

Marine Jean Augustin Accaron and others, as evidenced by their names or initialson the documents. Also, the presence of abstracts at the top of some dispatchessuggests that they were screened by lower-level officials prior to reaching theMinister. See, for example, Kerlérec to Minister, New Orleans, June 24, 1755. AN,C13a 39, folio 104-6vo, LCRP reel 46.

9

The analysis and recreation of Kerlérec's cipher allows, for thefirst time, a way to verify the accuracy with which the Ministry ofthe Marine decrypted the subject dispatches. In the course of thisinvestigation, the author, using the recreated code table, inde-pendently decrypted each of the thirty-three dispatches and thencompared the results to the plaintext versions prepared by theministry. This brought to light a number of errors in the minis-try's versions.

In dispatch no. 86, dated October 9, 1755, Kerlérec describesthe location of newly established English posts in Georgia.19 Theministry's decoded version reads, in translation, "They have justestablished settlements on a river two day's [journey] from theKaoüitas. . . ." An examination of the code, however, reveals amore exact description: "They have just established settlementson the Okkonis River, two day's [journey] from the Kaouyta. . . ."

In dispatch no. 91, dated October 18, 1755, Kerlérec speaks tothe shortages of cannoneers in Louisiana.20 The ministry's decod-ed version reads, "As for cannoneers, we have asked for them forthe [lower Mississippi] river as well as for Mobile." The actualcode conveys a very different message: "As for cannoneers, wehave only one for the entire river and one other at Mobile."

The mechanism by which some such decoding errors were madeis often quite apparent. For example, while decoding the fourthpage of dispatch no. 86, the ministry's cipher clerk lost his placein the document and skipped from the end of line 11 to the end ofline 12, failing to decode the intervening ciphertext.21 The minis-try's version reads, "I repeat to you again, Your Grace, the essen-tial needs for artillery according to the table of the posts. . . ." Thecode, however, reads, "I repeat to you again, Your Grace, the es-sential needs of the colony, which consist of artillery according tothe table of the posts. . . ."

Translations of several of Kerlérec's encoded dispatches havebeen previously published. Most notably, seventeen of the thirty-two contained in the Colonies C13a series appear in translation

19Kerlérec to Minister, New Orleans, October 9, 1755. AN, C13a 39, folio 60-62vo, LCRP reel 46.20Kerlérec to Minister, New Orleans, October 18, 1755. AN, C13a 39, folio 69-

70vo, LCRP reel 46.21Kerlérec to Minister, New Orleans, October 9, 1755. AN, C13a 39, folio 60-

62vo, LCRP reel 46.

10

in the fifth volume of Mississippi Provincial Archives.22 Thosetranslations, however, were made from the decoded versions pre-pared by the Ministry of the Marine, not from the originalciphertext. Thus, decoding errors made by the ministry were car-ried forward in the translations. Consider, for example,Kerlérec's dispatch no. 150, dated October 21, 1757, in which thegovernor described the first work done at the site of Fort Ascen-sion, later renamed Fort Massiac.23 The translation appearing inMississippi Provincial Archives indicates that the fort was "rein-forced with stone."24 This is in agreement with the ministry's de-coded version, which describes the fort as de pierre rendoublé.The ciphertext, however, is 116.169.347.230.567.642.497.483.,which is de pieux rendoublé, meaning "reinforced with pickets." Asimilar error can be found in dispatch no. 135, dated January 28,1757, in which Kerlérec speaks of his inability to provide tradegoods to the Indians.25 The translation appearing in MississippiProvincial Archives reads, "If the Abnakis keep their word withus, I shall be much more embarrassed."26 This agrees with theministry's decoded version but propagates an error involving thename of the Indian tribe. The code is 95.626.26.596, which is notAbnakis, but Cheraki (Cherokee).

Another example is found in dispatch no. 308, dated June 24,1762.27 In one part of the dispatch, Kerlérec speaks of havingsent Sieur Lantagnac to the Cherokee nation. The translationappearing in Mississippi Provincial Archives reads, ". . . I orderedhim to have my letters passed on to the Illinois so that he mightcarry out the same operations among the nations that surroundit."28 This is in general agreement with the ministry's decoded

22Mississippi Provincial Archives: French Dominion, Dunbar Rowland, A. G.Sanders, and Patricia Kay Galloway, eds., 5 vols. (Baton Rouge, 1984), vol. 5.23Kerlérec to Minister, New Orleans, October 21, 1757. AN, C13a 39, folio 277-

79vo, LCRP reel 46.24Mississippi Provincial Archives, 5:188-90.25Kerlérec to Minister, New Orleans, January 28, 1757. AN, C13a 40, folio 27-8,

LCRP reel 47.26Mississippi Provincial Archives, 5:180.27Kerlérec to Minister, New Orleans, June 24, 1762. AN, C13a 43, folio 78-83,

LCRP reel 51.28Mississippi Provincial Archives, 5:278-80.

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version; however, the original ciphertext carries a slightly differ-ent meaning: ". . . I ordered him to have my letters forwarded tothe Illinois [post] for M. de Neyon, who commands there, so thathe takes the same action toward the nations that surround him."

Decoding errors were not the only ones identified. In several ofthe dispatches, errors were made during the coding process. Thisis easy to understand when one considers that three or four cop-ies of each dispatch might be produced, each involving the mind-numbing task of copying line after line of code numbers. Themost frequent error was the transposition of digits, for example,652 (ca) for 562 (ac). Another, somewhat less common, error wasthe omission or repetition of code elements. It also appears thatsome code elements were omitted on purpose, perhaps becausethe cipher clerk judged them unnecessary. For example, in dis-patch no. 72, dated June 24, 1755, the code for s (49 or 207) wasomitted at the end of almost all of the plural nouns and adjec-tives.29 For the most part, such transpositions, repetitions, oromissions were easily recognized and could be corrected by theministry's cipher clerk during decoding.

Despite the relatively unsophisticated nature of Kerlérec's ci-pher, the weaknesses in the way it was used, and the introduc-tion of errors during the coding or decoding processes, the systemseems to have worked well enough. If nothing else, it kept sensi-tive documents from being easily read by the couriers, ship's of-ficers, clerks, and others who might have handled them while intransit. This was the case, for example, with correspondencedealing with internal issues not specifically related to the colony'ssecurity. Toward the end of 1758, a dispute arose betweenKerlérec and the newly arrived ordonnateur, Vincent deRochemore, that came to be known in France as the Affaire de laLouisiane, entailing the exchange of charges and counterchargesbetween the two and the formation, among the military and civil-ian officers in New Orleans, of camps loyal to one or the other ofthe two belligerents.30 Four of Kerlérec's encoded dispatches dealwith this subject. One in particular, dispatch no. 206, dated Ju-ly 3, 1759, is devoted entirely to the behavior of Rochemore and

29Kerlérec to Minister, New Orleans, June 24, 1755. AN, C13a 39, folio 104-06vo, LCRP reel 46.30For an exhaustive treatment of the subject, see Hervé Gourmelon, Le Cheva-

lier de Kerlérec, 1704-1770: L'affaire de la Louisiane . . ., 2nd ed. (Paris, 2004).

12

those loyal to him and requests their recall to France.31 For thatparticular dispatch, encoding was used because the documentwas to be entrusted to a Spanish priest bound for Havana andwould, no doubt, have passed through many hands before reach-ing the Minister of the Marine.

It is difficult to judge how effective Kerlérec's code was in keep-ing military matters secret, but there was certainly a need to doso. Early in the Seven Years' War, the English had made plans toinvade Louisiana, and in February 1758 an actual authorizationfor such action had been conveyed to Gen. Jeffrey Amherst.32

Certainly the colony was ripe for such an invasion. It is evident,considering just the intelligence contained in Kerlérec's encodeddispatches that, throughout the period of the Seven Years' War,Louisiana was perpetually short of resources, constantly strug-gling to hold onto its Indian allies, and would have been all butdefenseless against a determined English attack, especially onesupported by naval forces directed at either Mobile or New Orle-ans. We find, for example, in Kerlérec's coded dispatch of Ju-ly 13, 1759—one of the three for which no plaintext annotationshave been found—that the Balize post, built originally to guardthe primary entrance into the Mississippi River, had beenstripped of all its cannons, save two for signaling, and the com-mander there had been directed to abandon the post in the eventof an English attack.33 The fact that the English failed to exploitthis and other such vulnerabilities may be due, at least in part, tothe effectiveness of Kerlérec's cipher.

31Kerlérec to Minister, New Orleans, July 3, 1759. AN, C13a 41, folio 81-2,LCRP reel 48.32Pitt to Amherst, Whitehall, February 10, 1759, published in Gertrude S. Kim-

ball, ed., Correspondence of William Pitt, When Secretary of State, with ColonialGovernors and Military and Naval Commissioners in America, 2 vols. (London,1906), 2:37-8.33Kerlérec to Minister, New Orleans, July 13, 1759. AN, C13a 41, folio 87-98vo,

LCRP reel 48.

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Table 1. Dispatches used in the author's analysis34

Dispatchnumber

Copynumber

Date A.N., ColoniesC13a reference

LCRPReel no.

72 June 24, 1755 39, folio 104-6vo 4686 1 October 9, 1755 39, folio 60-62vo 4687 1 October 10, 1755 39, folio 63-64 4691 2 October 18, 1755 39, folio 69-70vo 46

103 2 April 1, 1756 39, folio 146-48 46117 1 July 22, 1756 39, folio 181-82 46127 3 December 12, 1756 39, folio 190-91 46135 2 January 28, 1757 40, folio 27-28 47138 3 March 13, 1757 39, folio 258-59 46141 3 March 16, 1757 39, folio 262-63 46143 1 May 12, 1757 39, folio 246-46vo 46144 3 May 13, 1757 [See note 7] 1145 1 August 28, 1757 40, folio 34-35vo 47146 1 September 10, 1757 39, folio 247-49 46150 1 October 21, 1757 39, folio 277-79vo 46

2 August 12 and 23, 1758 40, folio 31-33vo 47194 May 6, 1759 41, folio 51-52vo 48194 2 November 10, 175935 41, folio 144-45vo 48206 3 July 3, 1759 41, folio 81-82 48207 1 July 13, 1759 41, folio 87-98vo 48215 2 September 17, 1759 41, folio 111-11vo 48226 1 December 8, 1759 41, folio 147-49vo 48228 2 June 12, 1760 42, folio 48-53 50236 1 March 30, 1760 42, folio 10-11vo 50245 1 December 21, 1760 42, folio 83-85vo 50247 1 March 1, 1761 42, folio 203-4 50256 3 June 8, 1761 42, folio 217-20 50263 2 July 12 and 19, 1761 42, folio 229-30 50277 2 December 15, 1761 42, folio 267-69 50279 1 February 10, 1762 43, folio 25-25vo 51284 1 April 28, 1762 43, folio 30-32vo 51308 2 June 24, 1762 43, folio 78-83 51332 1 July 26, 1762 43, folio 90-91 51

34All dispatches except no. 146 are those of Kerlérec. Dispatch no. 146 is a jointdispatch drafted with Jean Baptiste Claude Bobé-Descloseaux, then performingthe functions of ordonnateur in the colony.35Except for its date and formatting, this dispatch is identical to Kerlérec's dis-

patch of May 6, 1759. It does not, however, contain plaintext annotations.

14

Table 2. Kerlérec's CipherA partial recreation of the table à déchiffrer used for

Kerlérec's correspondence during the period 1755-176236

36In reconstructing the code table, the author used word or word-fragmentspellings that were consistent with the orthography of the time. Thus, françoisinstead of français and anglois instead of anglais, the ending -ais(e) not beingformally adopted until the sixth edition (1835) of the Dictionnaire de l'Académiefrançaise.

2 indispensable4 convenable5 obstacle6 semblable9 tour

12 voyage14 ar16 ai17 entreprise19 el20 pas22 comman24 projet26 k27 force28 bi29 quand32 beaucoup33 guerrier34 vo35 peut36 feu37 pays39 praticable41 hiver42 homme43 opération45 roit46 ois47 cha48 du49 s50 ce51 op53 quelle54 dont55 son56 he57 sou58 idee59 le

60 p61 frappe62 grace63 to64 elle65 fort68 présent71 im72 tu73 magazin75 gi76 l78 ete79 regle80 il81 secours82 prochain84 honneur86 ru87 tranquil88 isle89 c90 tant92 borne93 ennemi95 che96 marchandise97 nouvelle98 rend99 Chactas

100 pour102 munition103 gout104 notre105 tout106 encore108 nos109 je111 prompt113 mouvement114 a

115 vi116 de117 ent118 qui119 la Louisiane122 usage123 qu124 particulier125 fais126 al127 françois128 plusieurs129 l130 seul131 poste132 terre133 place135 egal136 q137 vers138 troupe139 nt140 chose141 ailleurs142 pe144 suite145 h146 extraordinaire147 etre149 port150 habitant151 co153 ga154 oc155 la Vera Cruz156 di157 ir158 fe159 deffen163 sorte164 plan

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165 recu166 etat167 haut168 depuis169 pi172 service175 non177 nul178 e180 r181 fidélité183 verifi184 droit185 et186 fait187 z189 Espagne190 pre191 malheur192 interet195 bli196 sçavoir197 em198 considérable199 n200 objet202 corsaire204 nécessaire205 jamais206 puis207 s208 cu210 ecri211 genie212 impatience213 succes214 Anglois216 nation218 for219 fin220 sauvage221 la Jamaïque222 lettre223 tien224 be225 libre226 g227 peu228 ils229 bon230 r231 détachement232 m

233 aucun235 per236 meilleur237 hi238 ont240 Cuba241 bre242 assez243 établi244 quel245 d247 ordre249 doi250 o252 effort253 difficulte254 Mexique255 infor256 at257 déjà258 u259 St-Domingue260 li261 po262 incursion263 ouil264 t265 ho266 les267 oi268 enfin269 vu271 employ272 marque273 espagnol274 ge275 pris, prix277 par278 votre279 roy281 gouvernement283 paix284 se285 ton286 avec288 ex289 nu290 point292 nombre293 bâtiment294 trai296 in297 ve

298 la Mobile299 es300 France301 vaisseau302 ouvrage303 premier304 ment305 nègre306 cour307 go308 na309 autre310 so311 fusil313 decla314 monde315 on316 Nouvelle Orléans318 occasion320 nom321 batterie323 arme325 si327 conduite328 barri329 introdu330 fortifi331 allie334 f335 retard336 ordinaire337 depen339 faire340 eu341 querelle342 approuve344 aux345 vous346 do347 eux349 pu350 con351 nécessité352 depart353 y356 bou358 général361 loin362 mer363 charge365 affaire366 a367 aussi

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368 lors369 hors370 ne371 fo374 flûte375 celle376 fer378 monsieur379 jour380 obser381 disposition383 farine384 gagne385 faute387 juge388 vrai389 desti390 au391 escadre394 fois395 hu396 ro398 traite399 entre401 précaution402 rivière404 appo405 main406 soin407 re408 que409 avis410 jusques411 te412 ja414 ri415 loi416 Illinois417 nous419 v420 danger421 ensemble423 transport426 tion427 oit428 habi430 garde431 moyen432 intelligence433 ville434 Danemark435 après440 pendant

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