Sebastiano Foscarini to the Doge, Paris, 11 September 1680

At a glanceExisting decipherment · complete

The letter: Sebastiano Foscarini, Venetian ambassador in France, to the Doge, Paris, 11 September 1680: despatch no. 117, “P.S. Sola”, one page of cipher.
Where: Archivio di Stato di Venezia, IT ASVe 0045 010 Busta 30 f. 4; DECODE R1871. Catalogued as “England?”, 1555, under catalogue 264 together with R1873, a Rome despatch of 1558 in another cipher.
The cipher: Continuous digits that fall into three-digit groups: 612 groups, 211 different, from a table of about 300 codes. Not an alphabetical table.
How it was tried: Transcribed from the images, segmented, then attacked with several annealing solvers and an Italian language model. No Italian came out.
Why it resisted: One page is too short for a blind solution of a table this size, and the key is not on DECODE. Brice Dudout found the table is a syllabary in blocks of five consecutive codes with the blocks out of order, which an ordered-syllabary solver cannot find.
What it says: From Paolo Bonavoglia’s decipherment: rumoured Spanish reinforcements in the Milanese, and Louis XIV’s reported plan to raise the Pinerolo garrison to 6,000 men.
Credit: The decipherment is Paolo Bonavoglia’s. Brice Dudout reported his page back online; Satoshi Tomokiyo’s note on DECODE R1872 first pointed to him.

Until 14 October 2026 this despatch shared an entry with R1873, Alvise Mocenigo’s Rome despatch of 1558: a different cipher, with its own page.

01 The record

The two images of R1871 show one page of continuous digits under “Ser.mo Principe”, marked “#117 P.S. Sola” and signed “Sebastian Foscarini Amb.r”, dated at Paris in 1680. The dorse is addressed to the Doge and docketed “11 Sett. 1680 … n.o 117”. The record is not English and not of 1555: DECODE’s region and date seem to have been copied from the neighbouring record R1872 (Giovanni Michiel, Brussels, 1555).

The DECODE images are not in the public domain and may be published only with the archive’s permission, so none are reproduced here. The strip above is from the transcription made here.

02 The cipher

The page holds 23 lines and 1,839 digits. The rare digits 0, 7, 8 and 9 occur only in one position, and within each line that position is constant modulo 3 over long stretches: the digits are three-digit groups, and the jumps in phase are slips of the pen or of the transcription. Segmented that way the page gives 612 groups (593 of three digits), 211 of them different. The first digit runs 1–5 (6 is rare), the second 1–6 and the third 0–9, so the table holds about 300 codes between 110 and 569. The commonest groups are 156 (22 times), 517 (20), 256 (19), 152 (16) and 459 (15).

Bonavoglia says Foscarini’s cipher served at both Paris and Madrid, and calls it too regular and orderly. The table here is not ordered alphabetically, though: Sukhotin’s vowel test puts vowel-like and consonant-like codes side by side (151 and 156 vowel-like, 152–154 consonant-like).

03 How it was tried

Other segmentations: two-digit pairs (the gap parity is random) and self-delimiting tokens ending in 5–0 or 6–0. Annealing gave no Italian.
A monotone annealer for an ordered syllabary, 12 seeds, scored with a clean Italian 4-gram model. It recovers a synthetic ordered control only in part, and gives the same non-Italian text on every seed for the real page.
Free annealers, one letter per code and letter or syllable per code, 14 seeds: fluent-looking text that changes with every seed, the mark of overfitting.

211 free code values against 612 groups is beyond what an Italian language model can pin down for a homophonic, syllabic table. The page needs the key (in the ASVe Cifre, chiavi e scontri; the only Venetian key records on DECODE, R1788–R1790, are 16th-century tables and do not match), more ciphertext in the same key, or Bonavoglia’s decipherment.

04 The reading

Paolo Bonavoglia’s page on this despatch was offline during the attempt. Brice Dudout reported it back online on 27 October 2026, and its text is saved in the repository with an English translation. Bonavoglia gives the original as ASVe Senato, Dispacci Francia, filza 171A, and the Doge’s chancery decipherment as filza 166. He worked the table out from this and other despatches.

It is a postscript written after the despatch was signed. Foscarini passes on a report he cannot yet confirm: the Spaniards are adding troops in the Milanese, and Louis XIV means to raise the Pinerolo garrison to 6,000 men of the old regiments and spread 16,000 men over Dauphiné and Provence. The Duke of Mantua’s illness and a feared Spanish move on Casale are given as reasons, and munitions are said to be reaching Pinerolo by way of Savoy. Bonavoglia judges it a false alarm.

Brice Dudout rebuilt the table, which Bonavoglia does not publish: a syllabary in blocks of five consecutive codes, with the blocks in no order. It agrees with Bonavoglia’s text at 94.9% on held-out lines.

05 What remains open

Three number groups that Bonavoglia leaves open (“[Francesi?] 269?”, “114?” and the closing 202.106.100).
The key is not rebuilt here, and Bonavoglia’s text is not aligned group by group with the transcription made here: his ciphertext viewer still returned an error on 27 October 2026. Dudout’s table could be used to check lines 18–19 and 22 of the transcription.

Full texts

The transcription and the decryption of every document on this page, so that the reading can be used and checked. Short files are shown here; all are in the repository.

R1871, Sebastiano Foscarini, Paris, 11 September 1680, despatch no. 117 (this project's transcription; Paolo Bonavoglia's decipherment)

A postscript Foscarini added after signing his despatch: reports of Spanish reinforcements in the Milanese, and Louis XIV's reported plan to raise the Pinerolo garrison to 6,000 men and spread 16,000 over Dauphiné and Provence, with the Duke of Mantua's illness and a feared Spanish move on Casale; munitions reaching Pinerolo by way of Savoy. Read by Paolo Bonavoglia (crittologia.eu).

Transcription

tx.txt

L01 2005182452264595332633215174515475354622561435335951526355835915646225411465256
L02 252116143368245254443551152520262256151225516439368312152261558245517316459315
L03 4591433561535561673625681564621564393573204522624111652454592602523188368516463
L04 360433353156152517441317224245943615656920025444226815640225316546155992248167
L05 262146156349256159331165435540456435156416354195162253516151117387349256517364243
L06 366835433143252321152165233467356260517535435547320244256517535462256359156461
L07 459262226316531615325443722635172833592227459560152321443253517456517244142154
L08 4362531451562523556535433237456535144516461166152426349356256517517162119356152
L09 36621112261422263256366433445461359560252516317535433167115261559262459238152
L10 11145631525341116532025445942625625215444722245926156268540456435552283
L11 2003682565172226317434165320167362366461154433145262547165535462256143556417
L12 2605155583595354561672226516359261211643331845926124526135951831121521167253268
L13 1502614692564454615592024115321533434211532229817833359203460024032125445?2
L14 2631652622563544624633571561152621536152357517465165150317516359261520445462
L15 2545175244622602564335174645574242624111653064334301565174373563205174542532602
L16 4113122521545404564355345172602635174535594262561525203152514343173595433202523550538
L17 4332374565351442005354622561432461521563161422631652531672621463550156360454459260152156
L18 24414215443053714426241151526955346925625115114543553426043516542615615631614235636?2434535
L19 5651720416525532245164601451675191522103484394334415172514635334394355465356253256151145
L20 113318817533359515262242251245459262200551154156261559263467456132156156169153461553261153156
L21 2564453191521545172461532263151523681564622534391523595164591435535268456459167263366433461
L22 35926415115656915625331915155951843316533636815345?45953?5?64655583595?35?7435426256359560
L23 43935715051035882944349456211535456213152201106100

Decryption: SebFoscarini_Parigi16800911.html

Reading

R1871_reading.md

<!-- Reading of R1871 (Claude Opus 5.5, 27 Oct 2026): Paolo Bonavoglia's decipherment, as copied into r1871_bonavoglia.txt from crittologia.eu/storia/SebFoscarini_Parigi16800911.html (fetched 27 Oct 2026). His text verbatim, with his spaces and capitals; his open items left as he gives them. Not aligned with this project's transcription. -->

# R1871, Sebastiano Foscarini to the Doge, Paris, 11 September 1680, despatch no. 117, P.S. sola (Bonavoglia's decipherment)

## Reading

Sermo Principe

Dopo firmato il dispazia mi uiene mandato un auiso al quale se bene non poso prestare intiera fede per non hauere tempo di cercar nei riscontri tuttauia per l'inspetion che porta seco non deuo tralasciare di parteciparlo a Vostra Serenità

Sopra gli auisi che uengono continuamente d'Italia che li spagnoli acrescono considerabilmente di trupe nel Milanese il re che ha quantità di milizia in piedi mi uien auertito che habbia risoluto di rinforzare il presidio di Pinarolo sino a seimila huomini de uechi regimenti e di distribuire nel Delfinato e nella Prouenza sedecimila conbatenti per essere al ocasion che insorgiesero piu forte degli spagnoli stesi

Non è dificile che incontri nel uero la notizia che mi uiene scrita da un mio confidente dalla corte potendo hauere consigliate queste preuention il male del signor duca di Mantoua et il sospeto che tien uiuo l'abate Morel di qualche acidente inprouiso di sua uita e la diuulgation che nella passata di lui indisposition hauesero spagnoli meditato di spingiere in Casale cinque in seimila huomini

Mi uiene pure acenato che si continui a trasportare a Pinarolo munition da [Francesi?]269? ma queste sarano li metali che gia acenai nelle mie di 114? che si faceuano condure dal Mare per la parte di Sauoia per li quali si erano anco dimandati pasaporti

Starò atento quanto bisogna a così graue materia e procurerò di purificare non auisi per renderne miglior conto nella uentura a Vostra Serenità asicurandola che io non risparmio qualunque diligienza per l'adempimento del mio douere 202.106.100

Parigi li 11 Settre 1680  Sebastiano Foscarini Ambre

Translation

R1871_en.md

# R1871, Sebastiano Foscarini to the Doge, Paris, 11 September 1680, despatch no. 117, P.S. sola: English translation

Most Serene Prince,

After the despatch was signed, a report was sent to me. Although I cannot give it full faith, having no time to look
for confirmation, the weight it carries means I must not fail to pass it on to Your Serenity.

On the reports that keep coming from Italy that the Spaniards are considerably increasing their troops in the
Milanese, I am told that the King, who has a great number of soldiers under arms, has resolved to reinforce the
garrison of Pinerolo up to six thousand men of the old regiments, and to distribute sixteen thousand fighting men in
Dauphiné and Provence, so as to be ready, should the occasion arise, stronger than the Spaniards themselves.

It is not unlikely that the news written to me by a confidant of mine at court is true. These precautions may have
been advised by the illness of the Duke of Mantua, by the suspicion that the abbé Morel keeps alive of some sudden
accident to his life, and by the rumour that during his last illness the Spaniards had meant to push five or six
thousand men into Casale.

I am also given to understand that munitions continue to be carried to Pinerolo from [the French? 269?], but these
will be the metals I already mentioned in my letters of [114?], which were being brought from the sea by way of
Savoy, and for which passports had also been requested.

I shall watch so grave a matter as closely as it needs, and shall try to sift the reports so as to give a better
account of them to Your Serenity in the next post, assuring you that I spare no diligence in doing my duty.
202.106.100

Paris, 11 September 1680. Sebastiano Foscarini, Ambassador

06 Sources

DECODE R1871 (2 images, login).
Paolo Bonavoglia, “Decifra dispacci veneziani”, crittologia.eu: the list entry “1680-09-11: Dispaccio di ambasciatore Sebastiano Foscarini”; and his decipherment, “Dispaccio di Sebastiano Foscarini 11 set 1680”.
Brice Dudout, email of 27 October 2026 (the page back online; the five-code block table).
Satoshi Tomokiyo’s note on DECODE R1872.

Notes, transcription and solvers: targets/r1871/ in the repository.

Sebastiano Foscarini to the Doge, Paris 1680