Working notes · September 2026
Attempts on historical ciphers that are short, context-rich, and listed as unsolved. Started after Vals AI reported Claude Fable 5.1 reading Thomas Urquhart's Cyphral Distich; the question was whether the same approach, an agent plus a person checking its work, gets anywhere on the rest of the list.
Brussels / Vienna, 16 November 1635 and 22 February 1640
Substantially deciphered · residual gaps
Winter quarters at Trier, recruitment in Westphalia, and a request for 100,000 florins. A known Latin draft supplies the 1635 alphabet; a separate syllable supplement extends the reading through both 1640 pages. Uncertain glyphs and copying errors remain explicit.
Ottobon to Mocenigo, 27 April 1589 · BNE Mss/994, ff. 34–38
Substantially deciphered
A Venetian dispatch to the ambassador in France, with the enclosed reply to Henri III's envoy Gondi, who had come to ask for aid and a league. The Republic's surviving key, Ziffra prima, reads all seven cipher pages. Intercepted in Savoy in 1589 and broken then by Philip II's cipher secretary, whose working was lost.
Manuscript images, Italian and English side by side. Write-up, transcription, key excerpt and decoder.
Sir Richard Forster, 13 May 1644 · AD Val-d'Oise, 68 H 8
Deciphered
A ciphered passage in a letter by the treasurer of Henrietta Maria's household: counsel that preserving one's life is no failing before God. Mixed letter-and-number homophonic substitution, 207 symbols, three repairs. George Lasry and Norbert Biermann had read it earlier, and Robert Pitt published a key on 14 September 2026.
Ciphertext, French and English
With the 37 cipher words and the key. Write-up, solver and verification.
Vande Perre to de Bruyne, London, August–November 1653 · Birch, Thurloe State Papers i
Deciphered · two fragments open
The Dutch ambassador’s ciphered words, left as numbers in the intercepted English translations: a reasonable disposition to negotiate, the government awaiting orders with impatience, the new Council of State “reckoned to our advantage”, ten ships run, want of masts. A 22-letter alphabetical substitution recovered from the printed digits; Birch’s English glosses agree, and they fix the two code groups. In the earliest letter: “a character to open a lockt chest, ick segghe een cijffer”, I mean a cipher.
Moray to John Wood, Edinburgh, 13 July 1568 · BL Add MS 32091 f. 213v
Substantially deciphered
Four ciphered lines at the foot of a letter to the Regent's agent at Elizabeth's court, on the day Mary was moved out of Carlisle: her being allowed to stay there, and the sending home of Lord Fleming, "hes done greit evil"; the warning about her return remains partly unread. The conjectural ending “as our friends know” requires an unexplained sign to be omitted. A simple substitution with homophones and word-signs, read from the page image; two person-signs and the last word open.
Starhemberg, Paris, 23 May 1758 · Cryptiana transcription
Partially deciphered
A numerical cipher letter from Austria's ambassador at Versailles on drawing Spain into the Seven Years' War: the memorandum handed to Wall, Minorca as the price, a courier named Zinner. The 1752 Prima/Secunda key (DECODE R1695, R1698) gives connected German across the letter, but with no image of the original several joins do not parse and the exact full text is open.
Cipher rows, German and English
With the baseline key output, the proposed repairs and the checks. Write-up, keys, scripts and audit.