01 The letter
| Shelfmark | BnF Français 23054 · Blasco, 2 May 1597 |
|---|---|
| Sender | Juan Blasco de Aragon |
| Recipient | Not established |
| Date | 2 May 1597 |
| Language | Spanish |
| Report status | 3/4 pages transcribed; 1 more in part; 3/3 cipher pages deciphered |
| Ciphertext | 107 elements, 102 identified (95.3%) |
02 The key
16 codes, 16 letter values; 5 unidentified positions The key was recovered from the ciphertext alone.
03 The decipherment
f72r
por fuerça [?] con el parecer de todos los amigos. No ay duda que lo de venir con la princesa como dize V. E., siendo con las condiciones que V. E. apunta, seria lo que mejor estuviesse, pero hasta agora no ay nada en esto, a lo menos no lo sabemos.
Translation. By force [?], with the opinion of all our friends. There is no doubt that coming with the princess, as Your Excellency says, on the conditions Your Excellency specifies, would be best; but so far there is nothing in this, at least as far as we know.
f72v
Estamos tratando con don Baltasar de hacer algun presente a don Christoual, que es el que mand[a] todo, y no se perdera ocasion ninguna en que se ofrezca hacer el servicio de V. E. que no se haga.
Translation. We are discussing with Don Baltasar giving some present to Don Cristóbal, who commands everything; no opportunity to serve Your Excellency will be left unused.
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/btv1b9063548f/f134.item
- Folio matches the report: yes; cipher present: yes
- What we checked: Gallica f71r = Spanish letter, clear "Señor" heading, Blasco hand; cipher check on his f72r crop: "13.7.20.8.14 2.29.20 9.3 10.14.8.20.2.7.18.3" = venir con la princesa, matching his excerpt
- Verdict: confirmed (method key recovered from ciphertext-only, extent complete). The check is a sample, not a re-solution.
- Notes: Only 107 cipher elements (numbers in clear Spanish text); 16-value key from a short sample, so mostly context-driven. f71r itself is clear text; f72 holds most cipher.
05 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. 38; his other items are listed on his contributor card.
- The working folder:
targets/blasco1597/(his entry as extracted from the report, our spot-check,profile.json).