972Cyphersolver
luy [? ?] conte chi sa li oblighi che la con loro debe savere in qvesto
one key for two letters · che, con, et, per, qva, se: word signs · up to six signs for i and o

Sforza correspondence · homophonic cipher with word signs, mixed with clear Italian · 4 May 1446

Two Sforza letters of 4 May 1446

Francesco Sforza
toFrancesco Sforza

A reply to Francesco Sforza’s agent Zorzo del Maino and a letter from Milan about Cremona share one cipher, whose key George Lasry recovered from the ciphertext; most of both texts now gives sense.

Daniel Bourdeau · posted · updated

Method: key recovered from ciphertext-only · Extent: partial (87% of the cipher)

Contributed by George Lasry (solution, transcription) · Also credited · Giuseppe Mazzatinti (identification)

At a glanceCiphertext-only break · partial (87% of the cipher)

The letters
Two slips dated 4 May 1446. f. 68: a reply to what Zorzo (Giorgio) del Maino reported, writer and place unknown. f. 70: catalogued as Vincenzo Amidani to Francesco Sforza, from Milan.
Where
Bibliothèque nationale de France, italien 1583 ff. 68 and 70 (Archivio Sforzesco). f. 68 is DECODE R7898, without metadata; f. 70 is photographed at the top right of image P1 of R7899, which is catalogued under f. 75.
The cipher
One key for both: homophonic letters (up to six signs for i and o) and signs for the words or syllables che, con, et, per, qva and se. No word division. f. 68 mixes cipher runs with clear Lombard Italian.
How the key was found
George Lasry transcribed both slips with CTTS (CrypTool Transcriber and Solver), which generated the initial key from the ciphertext; Astra and Fable 5.1 improved the key and reading. No outside key or plaintext was used.
What it says
f. 68 answers Maino about Count Francesco’s obligations to others and the writer’s “secvreza”, and asks for eight or ten names from which trusted persons can be chosen. f. 70 reports a move against Cremona and what Venice might do.
Still open
39 sign occurrences in 13 sign classes, mostly at line openings (a fourteenth class, #30, was adopted as a null on 23 October 2026); three provisional values; the signature block of f. 70; a few clear words over damaged strokes. On f. 70 the open signs fall inside every clause of lines 1–5, so that letter is decoded, not read (reading audit, 22 October 2026).
Credit
Contributed by George Lasry (pull request 60). The project’s own attempt of 21 September 2026 failed; it is kept below.

01 The two slips

The Paris volumes italien 1583–1593 belong to the Archivio Sforzesco, bought by the Bibliothèque impériale in 1867. Giuseppe Mazzatinti’s inventory (Archivio storico lombardo X, 1883, p. 230) lists both slips under 1446: “f. 68. Risposta a quanto ha riferito Zorzo Maino (4 maggio). In cifre” and “f. 70. Lettera di Vincenzo Amidani a Fr. Sforza (Milano 4 maggio). In cifre.” That spring Sforza was under pressure in the Marche while Venice attacked the lands of Filippo Maria Visconti, duke of Milan; Sforza became duke himself in 1450.

f. 68 carries its date in clear at the head, “M°cccc°xlvj die iiij° may”, and alternates cipher runs with clear Italian. f. 70 is all cipher, in another hand, and ends with a deciphered date line, “mediolani die qvarto mai” (Milan, 4 May), which agrees with Mazzatinti. The year and the Amidani attribution come from the archive; the signature after the date has not been deciphered. Neither slip has a known contemporary decipherment, and no edition was found.

A small slip with a clear date line and two paragraphs of invented cipher signs mixed with clear Italian
f. 68, the whole slip: the date in clear at the head, a cipher line, then two paragraphs in which cipher runs alternate with clear phrases. Image: Bibliothèque nationale de France, italien 1583 f. 68, via DECODE R7898.

02 The key

The same key serves both slips. Each letter has one to six signs (i and o six each, n five); six signs stand for whole words or syllables: che, con, et (two signs), per (two), qva and se. Three values are provisional: (8) = l, (24) = n and (16) = in. Fourteen sign classes have no value. The key sheet below was drawn by Lasry in CTTS from the signs of both slips.

Key sheet: cipher signs under each letter from A to Z, then the word signs CHE, CON, ET, PER, QVA, SE and IN, and a row of unknown signs
The shared key: homophones under each letter, the word signs (“Nomenclature”), and the fourteen signs still without a value (“Unknown”). The column marked l holds the provisional (8). Image: George Lasry, CTTS key sheet (20 Oct 2026), signs cut from BnF italien 1583 ff. 68 and 70 via DECODE R7898 and R7899.

The key is not one of the Sforza keys on DECODE. In September all 208 key records of the Archivio di Stato di Milano, Carteggio Sforzesco cart. 1591, 1597 and 1598, were checked. Cart. 1597 no. 14, an eighteenth-century copy of “Angelus cum cifra Vincentij”, belongs to the same family (homophones, syllable and word signs, nulls), but its letter signs differ; no. 17, of 1447, differs too.

03 f. 68: the reply concerning Zorzo del Maino

The text below is Lasry’s edition. Bold is enciphered in the original; roman is clear writing or a bracketed supply; ? marks a sign without a value. The writer speaks as “nuy” and of the count in the third person, so the writer is not identified; Amidani’s name and Milan should not be carried over from f. 70.

M°cccc°xlvj die iiij° may
? ? ? l ? n resposta facta ad qvelo ha referito zorzo del maino o ?
? ? ? ? zorzo inteso cvelo ne hai resposto per parte del conte francisco et respondendo n-
on solamente ad qvele parte del consiglarlo per rispecti de li oblighi che lha con alt[r]i et
etcetera. Che nuy no sapiamo che obl[i]ghi siano n quisti ne cerchamo ne domandamo saverli ne o
tocha ad nuy cerchare questo, ma solum[ente] cerchamo con l’onor de dio et la secvreza nostra [aya? …]
luy ? ? conte chi sa li oblighi che la con loro debe savere in qvesto et se lvole et pvo fare
qvesto o non et volendo farne la secvreza gli havemo rechiesto siano contenti farghi
quello e dicto, et ad quello se refferemo n o ? ? n l
? ? ? ? ? ad la parte del elegere li confidenti ? ? respondemo che voglia essere contento mettere per scripto
? n o octo dece per che se tra loro no gli sera noma uno che no habia n ?intita le parte per-
che dubitano lo debiamo hauere ? per svspecto elezaremo qvelo n ? ? ?

English translation (Lasry)

4 May 1446
[…] Reply to what Zorzo del Maino has reported. […]
[…] Zorzo, having understood what you have answered us on behalf of Count Francesco, and replying not
only to those points about advising him in view of the obligations he has towards others, and
so forth. We do not know what obligations […] these are, nor do we seek or ask to know them, nor […]
does it fall to us to inquire into this; we seek only God’s honour and our security […].
He […] the count, who knows the obligations he has towards them, ought to know about this, and whether he wishes and is able to do
this or not; and if he wishes to give us that assurance, we have requested that they be willing to do for him
what has been stated, and to that we refer. […]
[…] As to the matter of choosing trusted persons, […] we reply that he should be willing to put in writing
[…] eight or ten [names], because, if among them there is only one who has not […] the parties, because
they fear we must regard him […] with suspicion, we shall choose that one. […]

The first cipher line restates the docket that Mazzatinti printed in 1883 (“Risposta a quanto ha riferito Zorzo Maino”). The contribution does not say that heading was used as a crib, so it is counted here as a check on the key, not its source. The clear and the cipher passages now join into one argument: the writer will not inquire into the count’s obligations to others, wants only security, and asks for a written list of eight or ten names, from which a single trusted person will be chosen.

The f. 68 slip with the key's value printed in red over each cipher sign
f. 68 with the decryption in red over each sign; question marks are the signs still without a value. Image: Bibliothèque nationale de France, italien 1583 f. 68, via DECODE R7898; overlay by George Lasry with CTTS.

04 f. 70: Milan, about Cremona and Venice

The letter is entirely in cipher. The date line deciphers as Milan, 4 May; the twenty-four signs after it, which should hold the signature, give letters that do not form a name. It is decoded, not read: on 23 October 2026 every sign was checked again on the DECODE image against Lasry’s overlay (no label changed), the sign class #30, which stands at line and clause boundaries in both letters, was taken as a null, and a partial reading was written (texts/f70_partial_reading.md). Sentences 1 and 3 hold, but the news clause of lines 4–5 rests on five sign classes with no value. The sixteen sibling 1446 cipher records of the volume (DECODE R7900–R7915) were opened; none uses this alphabet, so they cannot add occurrences. Lasry’s edition:

n o ? ilvstre signor mio a adviso vi l ? se mono ad fare contra cremona ?
credendo che la signoria de venetia et [fornendo?] se debia scoprirse contra lvi ?
ad adivtarvi et defender[v?]i et oltra cio che e fato de cremona gli do venire vnire
piv et altramente ad votvm che se e revnito ? ? ? da ? ad tvte le ?
sve ? et svbito sarano o o spazate tvte et sarano in campo et be-
nche sia certo che v per altra vaia de [ques?]te cose sara stata ? advisata
tamen per fare mio debito ne adviso v a la qvale me raconmando ? ? ? data
mediolani die qvarto mai ? ? p ? v a r qva c e et e ? s m n ? s t a ? ? m r

English translation (Lasry)

[…] My illustrious lord, I inform you […] to act against Cremona. […]
Believing that the government of Venice and [providing?] should declare itself against him […]
to assist you and defend [you?]; and besides what has been done concerning Cremona, […]
more, and otherwise as desired, [someone or something] has come together […] for all the […]
his […], and immediately they will all be [dispatched?] […], and they will be in the field; and although
I am certain that you will have been […] informed by another [route?] about [these?] matters,
nevertheless, to fulfil my duty, I inform you of them and commend myself to you. […] Dated
at Milan, on the fourth day of May. […]
The f. 70 slip, all in cipher, with the key's value printed in red over each sign
f. 70 with the decryption in red. The last line holds the date, “mediolani die qvarto mai”, and the signature block that does not yet give sense. Image: Bibliothèque nationale de France, italien 1583 f. 70, via DECODE R7899 image P1; overlay by George Lasry with CTTS.

05 How the key was recovered, and how much gives sense

Lasry transcribed the two slips in CTTS, which places a box on every sign: 839 boxes, of which 827 are cipher signs in 65 classes (425 on f. 68 in 52 classes, 402 on f. 70 in 48) and 12 are clear passages. CTTS generated the initial key from the ciphertext; Astra and Fable 5.1 then refined the key and the reading against the images and the context of both letters. The contribution’s verify.py re-checks every box, key value, edited segment and checksum, and passes.

The key gives a value to 780 of the 827 signs (94.3%, four of them provisional). That is assignment, not sense. Counted here word by word, 721 signs (87.2%) fall in words that make Italian: 380 of 425 on f. 68 (89.4%) and 341 of 402 on f. 70 (84.8%). The difference is the isolated letters at the edges of unknown signs, the signature block of f. 70, and the untranslated se mono, do and da. The counting script is measure_sense.py in the folder.

As a check against chance, the assigned values were scored with a Renaissance Italian language model (docs/_validate.py, it-cinquecento, four-letter sequences): the decryption scores −2.07 per letter, two hundred random keys of the same shape average −3.76 (best −3.18), and a key fitted to the shuffled ciphertext reaches only −2.54. The test passes.

Before this, the project’s own attempt of 21 September 2026 failed. It worked from a coarser draft transcription (404 and 390 signs, with diacritic variants merged), ran simulated annealing with the same language model under several constraints, tested word patterns, and checked all 208 Sforza keys on DECODE. Every run gave nonsense. That record, with the scripts, is in the folder.

06 What remains uncertain

The seventeen other 1446 cipher records from the same volume on DECODE (R7899–R7915, ff. 75–158: Nicodemo Tranchedini, “Angelus”, Stavoli and others) have not been transcribed. If any uses this key, they are the likeliest way to fix the open signs.

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.

f. 68 (DECODE R7898), 4 May 1446, reply concerning Zorzo del Maino's report

An unidentified writer replies to Zorzo del Maino's report concerning Count Francesco (probably Francesco Sforza): the count's obligations to others are his own affair, the writer seeks only God's honour and his own security, and asks for eight or ten names in writing from which trusted intermediaries could be chosen.

Transcription

1.txt

# 1.jpg
#35;(6);(4);(8);#41;#32;#4;#1;#9;#12;#13;#9;#5;#37;#26;#37;#33;#5;#15;#6;#17;#7;#19;#1;#20;#13;#24;#15;#4;#1;#26;#1;#4;(1);#5;#13;#10;#28;#4;#10;#28;#17;#27;#2;(2);#15;(7);#3;#14;#31;#35;
#25;(6);#36;#30;#10;#28;#4;#10;#28;#8;#3;#5;#1;#9;#14;#33;#19;#1;#20;#14;#3;#1;#24;#15;(7);#4;#1;#9;#12;#13;#9;#5;#13;(12);#12;#37;#4;#5;#1;#17;#27;#2;#33;#13;#3;#5;#27;#26;#4;#15;#3;#33;#8;#9;#33;#13;(5);#4;#1;#9;#12;#13;#3;#17;#1;#3;#17;#14;#32;
#31;#32;#9;#14;#2;#15;(2);#1;#3;#5;#1;#15;#17;#7;#19;#1;#20;#27;#12;#37;#4;#5;#1;#17;#1;#2;#38;#9;(1);#11;#2;#37;#4;#2;#13;(12);#4;(1);#9;#12;#1;#33;#5;#18;#17;#16;#2;(1);#13;#22;#2;(15);#11;#24;#8;#29;#2;#24;#37;#38;#6;#2;#5;(15);(5);
[Plaintext];#29;#28;#22;#2;#11;#24;(1);#9;(1);#15;#3;#13;#32;[Plaintext];#9;#6;#19;#1;#4;#2;(1);#3;#1;#31;
[Plaintext];(9);#2;#6;#9;#1;#33;#19;#4;#1;#10;#37;[Plaintext];
[Plaintext];#25;#36;#33;#14;#3;#5;#1;#33;#24;(1);#9;#15;#2;(1);#13;#22;#2;(13);#11;#24;(13);#29;#2;#6;#38;#2;#13;#4;#28;#17;#1;#22;#1;#9;#15;#19;#1;#4;#27;(16);#7;#19;#1;#9;#5;#13;(9);#9;#1;#2;#19;#13;#2;#1;(5);#12;#19;#14;#26;#15;#4;#16;
#7;#19;#1;#9;#5;#13;#14;#3;#13;#3;(5);#19;#13;#2;#1;#3;#17;#13;#26;#15;#4;#3;#1;#2;#6;#9;#1;#33;#19;#4;#1;#10;#15;[Plaintext];
[Plaintext];#32;#31;(4);#36;#32;(8);
#35;(6);(4);#25;#30;#37;#17;#2;#6;#12;#15;#4;#5;#1;#17;#1;#2;#27;#20;#1;#11;#1;#4;#16;#2;(1);#38;#26;(1);#17;#1;#3;#5;(1);#40;(11);#4;#1;#9;#12;#13;#3;#17;#1;(2);#13;#29;[Plaintext];
#36;#32;#31;#28;#33;#5;#14;#17;#1;#33;#1;#21;#29;[Plaintext];#32;#25;(13);#3;#5;#8;#5;#15;#2;#1;#12;#15;#4;#5;#1;#21;
#29;[Plaintext];#30;#21;#9;#19;#9;#12;#1;#33;#5;#13;#16;#20;#16;#10;#15;#4;#1;(2);#13;#7;#19;#1;#20;#28;#32;(10);#25;#30;
Decryption

1.txt

# 1.jpg
? ? ? l ? n r e s p o s t a f a c t a a d q v e l o h a r e f e r i t o z o r z o d e l m a i n o o ? 
? ? ? ? z o r z o i n t e s o c v e l o n e h a i r e s p o s t o per p a r t e d e l c o n t e f r a n c i s c o et r e s p o n d e n d o n 
o n s o l a m e n t e a d q v e l e p a r t e d e l con s i g l a r l o per r i s p e c t i d e l i o b l i g h i che l h a con a l t i et 
_ che o b l g h i s i a n o n _ s a v e r l i n e o 
_ et l a s e c v r e z a _ 
_ ? ? c o n t e c h i s a l i o b l i g h i che l a con l o r o d e b e s a v e r e in q v e s t o et s e l v o l e et p v o f a r e 
q v e s t o o n o n et v o l e n d o f a r n e l a s e c v r e z a _ 
_ n o ? ? n l 
? ? ? ? ? a d l a p a r t e d e l e l e g e r e l i con f i d e n t i ? ? r e s p o n d e m o che _ 
? n o o c t o d e c e per che _ n ? i n t i t a l e p a r t e per 
che _ ? per s v s p e c t o e l e z a r e m o q v e l o n ? ? ?
Decryption

edited.txt

1|? ? ? l ? n resposta facta ad qvelo ha referito zorzo del maino o ?
2|? ? ? ? zorzo inteso cvelo ne hai resposto per parte del conte francisco et respondendo n-
3|on solamente ad qvele parte del consiglarlo per rispecti de li oblighi che lha con alt[r]i et
4|etcetera. Che nuy no sapiamo che obl[i]ghi siano n quisti ne cerchamo ne domandamo saverli ne o
5|tocha ad nuy cerchare questo, ma solum[ente] cerchamo con l'onor de dio et la secvreza nostra [aya? …]
6|luy ? ? conte chi sa li oblighi che la con loro debe savere in qvesto et se lvole et pvo fare
7|qvesto o non et volendo farne la secvreza gli havemo rechiesto siano contenti farghi
8|quello e dicto, et ad quello se refferemo n o ? ? n l
9|? ? ? ? ? ad la parte del elegere li confidenti ? ? respondemo che voglia essere contento mettere per scripto
10|? n o octo dece per che se tra loro no gli sera noma uno che no habia n ?intita le parte per-
11|che dubitano lo debiamo hauere ? per svspecto elezaremo qvelo n ? ? ?
Translation

full_letter.md

# Two Sforza letters, 4 May 1446: Maino reply and Amidani companion

Transcribed by George Lasry with CTTS (CrypTool Transcriber and Solver), who also generated the initial key; the key and reading were improved by Astra and Fable 5.1.

Ciphertext is shown in bold.

### Contents

**First letter — f. 68 / R7898.** Unidentified sender to Zorzo del Maino; 4 May 1446; place of dispatch unknown.

The writer replies to Maino’s report concerning Count Francesco, probably Francesco Sforza. The discussion concerns the count’s obligations to others and the guarantees needed for the writer’s security. A second passage asks for eight or ten names from which trusted intermediaries could be chosen.

**Companion — f. 70 in R7899 P1.** Catalogued as Vincenzo Amidani to Francesco Sforza; Milan, 4 May 1446.

The letter reports prospective action against Cremona and discusses how the Venetian government might respond. It mentions assistance, defence and preparations for the field, although some details remain unclear. The writer closes by explaining his duty to keep the recipient informed; the signature remains unread.

### BnF italien 1583, f. 68 — Reply concerning Zorzo del Maino’s report

M°cccc°xlvj die iiij° may [4 May 1446; date written in clear]

1. **? ? ? l ? n resposta facta ad qvelo ha referito zorzo del maino o ?**

2. **? ? ? ? zorzo inteso cvelo ne hai resposto per parte del conte francisco et respondendo n-**

3. **on solamente ad qvele parte del consiglarlo per rispecti de li oblighi che lha con alt[r]i et**

4. etcetera. Che nuy no sapiamo **che obl[i]ghi siano n** quisti ne cerchamo ne domandamo **saverli ne o**

5. tocha ad nuy cerchare questo, ma solum[ente] cerchamo con l'onor de dio **et la secvreza** nostra [aya? …]

6. luy **? ? conte chi sa li oblighi che la con loro debe savere in qvesto et se lvole et pvo fare**

7. **qvesto o non et volendo farne la secvreza** gli havemo rechiesto siano contenti farghi

8. quello e dicto, et ad quello se refferemo **n o ? ? n l**

9. **? ? ? ? ? ad la parte del elegere li confidenti ? ? respondemo che** voglia essere contento mettere per scripto

10. **? n o octo dece per che** se tra loro no gli sera noma uno che no habia **n ?intita le parte per-**

11. **che** dubitano lo debiamo hauere **? per svspecto elezaremo qvelo n ? ? ?**

#### English translation

4 May 1446 [date written in clear]

1. **[???] Reply to what Zorzo del Maino has reported. [???]**

2. **[???] Zorzo, having understood what you have answered us on behalf of Count Francesco, and replying not**

3. **only to those points about advising him in view of the obligations he has towards others, and**

4. so forth. We do not know **what obligations [???]** these are, nor do we seek or ask **to know them, nor [???]**

5. does it fall to us to inquire into this; we seek only God’s honour **and** our **security** [???].

6. He **[???] the count, who knows the obligations he has towards them, ought to know about this, and whether he wishes and is able to do**

7. **this or not; and if he wishes to give us that assurance,** we have requested that they be willing to do for him

8. what has been stated, and to that we refer. **[???]**

9. **[???] As to the matter of choosing trusted persons, [???] we reply that** he should be willing to put in writing

10. **[???] eight or ten [names], because,** if among them there is only one who has not **[???] the parties, because**

11. they fear we must regard him **[???] with suspicion, we shall choose that one. [???]**


![Decryption in red — BnF italien 1583, f. 68](https://raw.githubusercontent.com/GeorgeLasry/cyphersolver/writeup-maino1446-lasry/targets/it1583/lasry2026/cryptiana/images/maino1446_decryption.png)


### BnF italien 1583, f. 70 — Companion letter catalogued as Vincenzo Amidani to Francesco Sforza

1. **n o ? ilvstre signor mio a adviso vi l ? se mono ad fare contra cremona ?**

2. **credendo che la signoria de venetia et** [fornendo?] **se debia scoprirse contra lvi ?**

3. **ad adivtarvi et defender[v?]i et oltra cio che e fato de cremona gli do venire vnire**

4. **piv et altramente ad votvm che se e revnito ? ? ? da ? ad tvte le ?**

5. **sve ? et svbito sarano o o spazate tvte et sarano in campo et be-**

6. **nche sia certo che v per altra vaia de** [ques?]**te cose sara stata ? advisata**

7. **tamen per fare mio debito ne adviso v a la qvale me raconmando ? ? ? data**

8. **mediolani die qvarto mai ? ? p ? v a r qva c e et e ? s m n ? s t a ? ? m r**

#### English translation

1. **[???] My illustrious lord, I inform you [???] to act against Cremona. [???]**

2. **Believing that the government of Venice and** [providing?] **should declare itself against him [???]**

3. **to assist you and defend [you?]; and besides what has been done concerning Cremona, [???]**

4. **more, and otherwise as desired, [someone or something] has come together [???] for all the [???]**

5. **his [???], and immediately they will all be [dispatched?] [???], and they will be in the field; and although**

6. **I am certain that you will have been [???] informed by another [route?] about** [these?] **matters,**

7. **nevertheless, to fulfil my duty, I inform you of them and commend myself to you. [???] Dated**

8. **at Milan, on the fourth day of May. [???]**


![Decryption in red — BnF italien 1583, f. 70](https://raw.githubusercontent.com/GeorgeLasry/cyphersolver/writeup-maino1446-lasry/targets/it1583/lasry2026/cryptiana/images/amidani1446_decryption.png)

### Shared key, letters horizontal

![Shared CTTS key, including provisional IN](https://raw.githubusercontent.com/GeorgeLasry/cyphersolver/writeup-maino1446-lasry/targets/it1583/lasry2026/cryptiana/images/maino1446_key.png)

f. 70 (DECODE R7899 image P1), Milan, 4 May 1446, catalogued as Vincenzo Amidani to Francesco Sforza decoded, not read

The writer reports prospective action against Cremona and how the Venetian government might declare itself, with help, defence and troops soon in the field, and closes that he writes to do his duty; dated Milan, the fourth of May; the signature is unread.

A mechanical decode with holes in most sentences: shown so that the transcription and the key can be checked and improved, not as a reading.

Transcription

IMG_R7899_I35638_P1.txt

# IMG_R7899_I35638_P1.png
#32;#31;#25;(1);(8);#19;#9;#5;#4;#1;#9;(13);#11;(20);(27);#4;(2);(1);(27);#6;#37;#17;#19;(1);#9;#14;(17);(1);#2;(25);#9;#27;(2);(27);(23);#14;#6;#17;#26;#37;#4;#27;#38;#5;#4;#6;#33;#4;#1;(2);#13;(20);#37;#30;
#33;#4;#1;#17;#27;(20);#17;(27);#29;#2;#37;#9;(1);#11;(20);(27);#4;(1);#37;#17;#27;#19;#1;(20);#27;#5;(1);#6;(5);[Plaintext];(14);#17;#1;#22;(1);#37;#9;#33;(27);#12;#4;(1);#4;#9;#27;#38;#5;#4;#37;#2;#19;(1);#25;
#37;#17;#6;#17;(1);#19;#5;#15;#4;#19;(1);(5);#17;#1;#26;#27;(20);#17;#1;#4;(1);(5);(27);#2;#5;#4;#6;#33;(1);(27);#29;#16;#26;#6;(21);#14;#17;#27;#33;#4;#1;(2);(27);(20);#6;#11;#2;(1);#17;(27);#19;#1;(23);(1);#4;#1;#19;(23);(1);#4;#1;
#12;(1);#19;(5);#6;#2;#5;#4;#6;(2);#1;(20);#5;#27;#15;#17;#19;#13;#5;#19;(2);#29;(14);#1;#4;#1;#19;(23);(1);#5;(27);#25;(4);(25);#17;#37;(19);#37;#17;#5;#19;(21);#1;#2;#16;#30;
#9;#19;#27;(26);(5);#9;#19;#22;(1);#5;(27);#9;#37;#4;#6;(24);(18);(18);(27);#9;#12;#37;#10;#6;#5;#1;#5;#19;(21);#1;(5);#9;#37;#4;#6;(24);#14;(1);(20);#33;#37;(2);#12;(27);(5);#22;#1;
(20);#29;#9;(1);#37;#33;#1;#4;#5;(18);#29;(17);(12);#37;#2;#5;#4;#37;#19;#15;(1);#6;#17;#1;[Plaintext];#5;#27;#33;(27);#9;#1;#9;#15;#4;#6;#9;#5;#15;#5;#6;#30;#37;#17;#19;(1);#9;#6;#5;#15;
#5;#37;(2);#1;(20);#21;#26;#37;#4;#1;(2);(1);(27);#17;#1;#22;(1);#5;(27);(20);#1;#37;#17;#19;(1);#9;(18);(17);#37;#2;#6;(28);#2;#1;(2);#1;#4;#6;#38;(2);#37;(20);#17;(27);#25;(6);(4);#17;#37;#5;#6;
(2);#1;#17;(1);(18);#2;#15;(20);(1);#17;(1);#1;(28);#4;#5;(27);(2);#37;(1);(4);#25;#12;(22);(17);#37;#4;(28);#33;#27;(5);#27;#30;#9;(2);(20);(6);#9;#5;#37;(22);(22);(2);#4;
Decryption

IMG_R7899_I35638_P1.txt

# IMG_R7899_I35638_P1.png
n o ? i l v s t r e s i g n o r m i o a a d v i s o v i l ? s e m o n o a d f a r e con t r a c r e m o n a ? 
c r e d e n d o che l a s i g n o r i a d e v e n e t i a et _ se d e b i a s c o p r i r s e con t r a l v i ? 
a d a d i v t a r v i et d e f e n d e r i et o l t r a c i o che e f a t o d e c r e m o n a g l i d o v e n i r e v n i r e 
p i v et a l t r a m e n t e a d v o t v m che se e r e v n i t o ? ? ? d a ? a d t v t e l e ? 
s v e ? et s v b i t o s a r a n o o o s p a z a t e t v t e et s a r a n o i n c a m p o et b e 
n che s i a c e r t o che v per a l t r a v a i a d e _ t e c o s e s a r a s t a t a ? a d v i s a t a 
t a m e n per f a r e m i o d e b i t o n e a d v i s o v a l a qva l e m e r a con m a n d o ? ? ? d a t a 
m e d i o l a n i d i e qva r t o m a i ? ? p ? v a r qva c e et e ? s m n ? s t a ? ? m r
Decryption

edited.txt

1|n o ? ilvstre signor mio a adviso vi l ? se mono ad fare contra cremona ?
2|credendo che la signoria de venetia et [fornendo?] se debia scoprirse contra lvi ?
3|ad adivtarvi et defender[v?]i et oltra cio che e fato de cremona gli do venire vnire
4|piv et altramente ad votvm che se e revnito ? ? ? da ? ad tvte le ?
5|sve ? et svbito sarano o o spazate tvte et sarano in campo et be-
6|nche sia certo che v per altra vaia de [ques?]te cose sara stata ? advisata
7|tamen per fare mio debito ne adviso v a la qvale me raconmando ? ? ? data
8|mediolani die qvarto mai ? ? p ? v a r qva c e et e ? s m n ? s t a ? ? m r
Decryption

f70_partial_reading.md

# f. 70 (DECODE R7899 image P1): letter catalogued as Vincenzo Amidani to Francesco Sforza, Milan, 4 May 1446 — partial reading

Rests on: George Lasry's CTTS sign transcription and the shared key (`../lasry2026/ctts/transcription/IMG_R7899_I35638_P1.txt`,
`../lasry2026/ctts/key.txt`), decoded in `../lasry2026/ctts/decryption/IMG_R7899_I35638_P1.txt`, re-checked sign by sign
on 23 Oct 2026 against the DECODE image P1 (3702 x 2590, fetched with the project cookie) and Lasry's overlay
(`../lasry2026/cryptiana/images/amidani1446_decryption.png`). One key change: **#30 = null** (see the reread log). No
contemporary decipherment, clear copy or edition exists (Mazzatinti 1883 gives the heading only).

The cipher writes one sign for u and v; it is given here as u or v by position (a transcription convention, not a
spelling change). Holes: `[(25)]`, `[#25]` etc. = a sign class with no key value, `[?word]` = partly carried,
`[…]` = unread. No word is supplied.

**Not read**: the sentences of lines 1-5 hold only in part (the clause of lines 4-5 has three sign classes without a
value), and the signature is unread. This stays *decoded, not read*.

## Reading

[N O #25] Illustre signor mio, a adviso V. il [(25)] se mono ad fare contra Cremona, credendo che la Signoria de Venetia et [?fornendo] se debia scoprirse contra lui ad adiutarvi et defender[?v]i.

Et oltra cio che e fato de Cremona gli do venire unire piu, et altramente ad votum, che se e reunito [#25] [(4)] [(25)] da [(19)] ad tute le sue [(26)], et subito sarano o o spazate tute et sarano in campo.

Et benche sia certo che V. per altra vaia de [?ques]te cose sara stata advisata, tamen per fare mio debito ne adviso V., a la quale me raconmando. [#25] [(6)] [(4)] Data Mediolani die quarto mai.

## Signature (unread)

[(4)] [#25] p [(22)] v a r qua c e et e s m n [(6)] s t a [(22)] [(22)] m r

## Notes

- `V.` stands alone for *Vostra Signoria* (lines 1, 6, 7: *adviso V.*, *che V. per altra via*, *ne adviso V. a la quale*).
- Sense hypotheses, **not adopted** (each sign class occurs once or twice in f. 70 and nowhere in f. 68 with a
  context that tests it; flagged for review): (25) = *Duca* (*il Duca se move ad fare contra Cremona*; Filippo Maria
  Visconti moved against Sforza's Cremona in 1446); (19) = *ordine* (*da ordine ad tute le sue*); (26) = *gente*
  (*le sue gente*); *se mono* = *se move*.
- `#25`, `(4)`, `(6)` stand in clusters at openings and closings in both letters (f. 70 *me raconmando #25 (6) (4) data*;
  f. 68 *#35 (6) (4) ... ad la parte*), consistent with nulls or a closing formula; not adopted (f. 68 l. 10 *n #25
  intita* is undecided).
- The signature: no assignment of the open classes makes *Vincentius de Amidanis* or any other name of the
  sender; Mazzatinti's attribution is not confirmed by the cipher.
Translation

full_letter.md

# Two Sforza letters, 4 May 1446: Maino reply and Amidani companion

Transcribed by George Lasry with CTTS (CrypTool Transcriber and Solver), who also generated the initial key; the key and reading were improved by Astra and Fable 5.1.

Ciphertext is shown in bold.

### Contents

**First letter — f. 68 / R7898.** Unidentified sender to Zorzo del Maino; 4 May 1446; place of dispatch unknown.

The writer replies to Maino’s report concerning Count Francesco, probably Francesco Sforza. The discussion concerns the count’s obligations to others and the guarantees needed for the writer’s security. A second passage asks for eight or ten names from which trusted intermediaries could be chosen.

**Companion — f. 70 in R7899 P1.** Catalogued as Vincenzo Amidani to Francesco Sforza; Milan, 4 May 1446.

The letter reports prospective action against Cremona and discusses how the Venetian government might respond. It mentions assistance, defence and preparations for the field, although some details remain unclear. The writer closes by explaining his duty to keep the recipient informed; the signature remains unread.

### BnF italien 1583, f. 68 — Reply concerning Zorzo del Maino’s report

M°cccc°xlvj die iiij° may [4 May 1446; date written in clear]

1. **? ? ? l ? n resposta facta ad qvelo ha referito zorzo del maino o ?**

2. **? ? ? ? zorzo inteso cvelo ne hai resposto per parte del conte francisco et respondendo n-**

3. **on solamente ad qvele parte del consiglarlo per rispecti de li oblighi che lha con alt[r]i et**

4. etcetera. Che nuy no sapiamo **che obl[i]ghi siano n** quisti ne cerchamo ne domandamo **saverli ne o**

5. tocha ad nuy cerchare questo, ma solum[ente] cerchamo con l'onor de dio **et la secvreza** nostra [aya? …]

6. luy **? ? conte chi sa li oblighi che la con loro debe savere in qvesto et se lvole et pvo fare**

7. **qvesto o non et volendo farne la secvreza** gli havemo rechiesto siano contenti farghi

8. quello e dicto, et ad quello se refferemo **n o ? ? n l**

9. **? ? ? ? ? ad la parte del elegere li confidenti ? ? respondemo che** voglia essere contento mettere per scripto

10. **? n o octo dece per che** se tra loro no gli sera noma uno che no habia **n ?intita le parte per-**

11. **che** dubitano lo debiamo hauere **? per svspecto elezaremo qvelo n ? ? ?**

#### English translation

4 May 1446 [date written in clear]

1. **[???] Reply to what Zorzo del Maino has reported. [???]**

2. **[???] Zorzo, having understood what you have answered us on behalf of Count Francesco, and replying not**

3. **only to those points about advising him in view of the obligations he has towards others, and**

4. so forth. We do not know **what obligations [???]** these are, nor do we seek or ask **to know them, nor [???]**

5. does it fall to us to inquire into this; we seek only God’s honour **and** our **security** [???].

6. He **[???] the count, who knows the obligations he has towards them, ought to know about this, and whether he wishes and is able to do**

7. **this or not; and if he wishes to give us that assurance,** we have requested that they be willing to do for him

8. what has been stated, and to that we refer. **[???]**

9. **[???] As to the matter of choosing trusted persons, [???] we reply that** he should be willing to put in writing

10. **[???] eight or ten [names], because,** if among them there is only one who has not **[???] the parties, because**

11. they fear we must regard him **[???] with suspicion, we shall choose that one. [???]**


![Decryption in red — BnF italien 1583, f. 68](https://raw.githubusercontent.com/GeorgeLasry/cyphersolver/writeup-maino1446-lasry/targets/it1583/lasry2026/cryptiana/images/maino1446_decryption.png)


### BnF italien 1583, f. 70 — Companion letter catalogued as Vincenzo Amidani to Francesco Sforza

1. **n o ? ilvstre signor mio a adviso vi l ? se mono ad fare contra cremona ?**

2. **credendo che la signoria de venetia et** [fornendo?] **se debia scoprirse contra lvi ?**

3. **ad adivtarvi et defender[v?]i et oltra cio che e fato de cremona gli do venire vnire**

4. **piv et altramente ad votvm che se e revnito ? ? ? da ? ad tvte le ?**

5. **sve ? et svbito sarano o o spazate tvte et sarano in campo et be-**

6. **nche sia certo che v per altra vaia de** [ques?]**te cose sara stata ? advisata**

7. **tamen per fare mio debito ne adviso v a la qvale me raconmando ? ? ? data**

8. **mediolani die qvarto mai ? ? p ? v a r qva c e et e ? s m n ? s t a ? ? m r**

#### English translation

1. **[???] My illustrious lord, I inform you [???] to act against Cremona. [???]**

2. **Believing that the government of Venice and** [providing?] **should declare itself against him [???]**

3. **to assist you and defend [you?]; and besides what has been done concerning Cremona, [???]**

4. **more, and otherwise as desired, [someone or something] has come together [???] for all the [???]**

5. **his [???], and immediately they will all be [dispatched?] [???], and they will be in the field; and although**

6. **I am certain that you will have been [???] informed by another [route?] about** [these?] **matters,**

7. **nevertheless, to fulfil my duty, I inform you of them and commend myself to you. [???] Dated**

8. **at Milan, on the fourth day of May. [???]**


![Decryption in red — BnF italien 1583, f. 70](https://raw.githubusercontent.com/GeorgeLasry/cyphersolver/writeup-maino1446-lasry/targets/it1583/lasry2026/cryptiana/images/amidani1446_decryption.png)

### Shared key, letters horizontal

![Shared CTTS key, including provisional IN](https://raw.githubusercontent.com/GeorgeLasry/cyphersolver/writeup-maino1446-lasry/targets/it1583/lasry2026/cryptiana/images/maino1446_key.png)

Key: key.txt

07 Sources

The CTTS files, the measurement and escalation scripts, and the September attempt are in the repository folder targets/it1583/.