01 The letter
| Shelfmark | BnF Français 3613 · Sega, ff148r–v |
|---|---|
| Sender | Filippo Sega |
| Recipient | Cardinal Caetano |
| Date | 9 January 1591 |
| Language | Italian |
| Report status | 1/2 pages transcribed; Deciphered |
| Ciphertext | 100 elements, 100 identified (100.0%): 99 plaintext codes and 1 null. |
02 The key
29 plaintext codes and 1 null; published historical key 65.
- Key elsewhere
- Published historical key elsewhere: Meister, Die Geheimschrift im Dienste der päpstlichen Kurie (1906), key 65, pp. 435–436.
03 The decipherment
f148v, complete enciphered passage and cleartext opening
Che Lignerac è stato inuiato d'ordine di Umena in Poitu et Bretagna a solecitar la impresa di Tours per doue ua anco a questi efeto un religioso acciò se l uno fose impedito l altro pasi.
Translation. Lignerac has been sent by order of Umena to Poitou and Brittany to press the undertaking at Tours. A religious man is also going there for this purpose, so that if one were prevented, the other might get through.
04 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 A. Image checked: https://gallica.bnf.fr/ark:/12148/btv1b90582263/f158.item
- Folio matches the report: yes; cipher present: yes
- What we checked: f148v (canvas f158) after clear "Che Lignerac e stato inuiato di ordine di": "12 8.. omega 33 32+ 28 37 38 41 21 35 24 37 42 26 31 42" with Meister key 65 -> [Umena] in Poitu et Bretagna, matching his excerpt; f148r clear text (Navarre, Christmas mass at St Denis) matches contents
- Verdict: confirmed (method read with known key, extent complete). The check is a sample, not a re-solution.
- Notes: Key printed by Meister 1906 (key 65), so a published-key reading. Only 100 cipher elements. Cited link f157 is f148r (clear); cipher is on f148v = canvas f158.
05 Notes and corrections
The cipher is on f148v, Gallica canvas f158. The report links f157, which is f148r (clear text).
06 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. 46; his other items are listed on his contributor card.
- f148v, the cipher (canvas f158; the report links f157 = f148r, clear text)
- The working folder:
targets/sega1591/(his entry as extracted from the report, our spot-check,profile.json).