01 The letter
| Shelfmark | BnF Français 3252 · ff36r–37r |
|---|---|
| Sender | Lodovico Birago |
| Recipient | Duke of Nevers |
| Date | 5 April 1571 |
| Language | Italian |
| Report status | 3/3 pages transcribed; 3/3 cipher pages deciphered in part |
| Ciphertext | 923 elements transcribed, 805 identified (87.2%) |
02 The key
60 symbols: 56 letter signs, 1 word sign, 3 nulls
- Key elsewhere
- Different volumes: Français 4702 f37 and Français 3251. Cryptiana’s Ceppo–Nevers key. · Source · Cryptiana: Ceppo–Nevers key
03 The decipherment
f36r, three complete cipher lines 7–9
…tempo che io ui dico questo il ? hauendomi riferto l'ho rimandato a Turino per uedere se li e posible di cauarne qualche particolarita, ma la E.sa Vos…
Translation. …the time when I tell you this. The ? having reported it to me, I sent him back to Turin to see whether he could obtain some details, but Your Excellency…
04 Plaintext and other sources
Where a decipherment or clear copy already existed, as George Lasry gives it:
- Interlinear plaintext
- Interlinear plaintext above the cipher signs, clearly visible in the native manuscript scans.
05 Our check
This result is George Lasry’s. This project did not re-solve the cipher: it checked one sample against the Gallica image and recorded what it found.
- Batch B. Image checked: https://openapi.bnf.fr/iiif/image/v3/ark:/12148/btv1b9060232m/f37/full/1600,/0/default.jpg
- Folio matches the report: yes; cipher present: yes
- What we checked: Canvas 37 shows f36r of the letter (Italian, "Il sig. Biagio..."), with cipher blocks identical to his crops; faint letter-by-letter interlinear visible over the signs, but I did not decode lines 7-9 sign by sign
- Verdict: partly confirmed (method read after matching with key from external sources, extent partial). The check is a sample, not a re-solution.
- Notes: Key matched from fr. 4702 f37 / fr. 3251 and the Cryptiana Ceppo-Nevers key; 87.2% identified. His meta labels the btv1b9060232m link as fr. 4702 key, but it is the letter itself.
06 Notes and corrections
Gallica btv1b9060232m image 37 is the letter (f36r), not the Fr. 4702 key the report labels it as. Sibling of targets/birago (Fr. 3251).
07 Sources
- George Lasry, with ChatGPT Astra 6 and Anthropic Opus 5.5, BnF cipher research, 10 October 2026 (sent to Daniel Bourdeau on 13 October 2026 for publication here), p. 132; his other items are listed on his contributor card.
- image 37 is the letter itself, f36r (the report labels this link as the Fr. 4702 key)
- image checked in the spot-check
- The working folder:
targets/birago1571/(his entry as extracted from the report, our spot-check,profile.json).