972Cyphersolver

Contributors · 56 people · 523 credits

Contributors

The ledger is a shared project. Anyone can add to it at four levels: a solution to a cipher already listed, a new unsolved cipher, a new cipher with its solution, or an independent check of a reading already here. Every write-up names who contributed and whose keys or decipherments it used; this page adds them up.

How to contributeWhoContributions in detailWhat the work builds onWaiting for a check

Daniel Bourdeau and contributors · posted · updated

01 Who has contributed

Daniel Bourdeau runs the project (302 of its own targets). 55 people are credited on 208 targets; 124 of those are also among the project’s own, credited because a reading there used their key, decipherment or pointer, so the two figures overlap and do not add up to the total. 155 of the credits are direct contributions (a solution, a new cipher, a verification, a key correction, a transcription, an identification or a pointer to a source); the rest record whose key, decipherment or earlier solution a reading used. A count is the number of targets; click it for the write-ups.

ContributorTargetsSolutionsNew ciphersVerificationsKeys correctedTranscriptions, identificationsPointersKeys usedEarlier solutions
Daniel Bourdeau project lead302own targets by outcome: key recovered here 73 · read with an outside key or decipherment 143 · not solved 62 · not applicable 24
George Lasry10959·1·163412
Satoshi Tomokiyo70····1915347
Arya Sanketbhai Patel88·······
Feyseel Nur853111···
Norbert Biermann8····1142
WAINUT41·3·1···
Nils Kopal4······22
Juan Carlos Galende Díaz3····1·2·
Mírka3·····111
Thomas Bosbach3······21
Wanruo Luo3······12
Satoru21···11··
Larry Beck22·······
Richard Bean2····111·
alejandrozarco22·······
NoAutopilot211·····1
Thomas Ernst2····1··1
Ajaydas Devadas2······2·
Judit W. Somogyi2······2·
Michelle Waldispühl2······11
Paolo Bonavoglia2······2·
Robert Pitt2······2·
Brice Dudout11···1···
Robert Węglarek1···11···
setsunaatto11·1·····
Adam Wright1·····1··
Andrew Aymeloglu1·····1·1
Angus Robinson11·······
David Scheers1····1···
Francesco Senatore1····1···
Frode Weierud1····1···
Ilya1····1···
Joe1····1···
Klaus Schmeh1····1···
Sofia Pettersson1····1···
wanglu20161····1···
yuanyi-3501·····1··
Alexandre Pillon1······1·
Anne-Simone Rous1·······1
Christof Rieber1·······1
David Vierra1······1·
Gerd1·······1
Ingo Niebel1······1·
Ivan Parisi1·······1
Jozef Krajčovič1·······1
Lance Estes1·······1
M. W. Kaczka1······1·
Matthew Brown1······1·
Max Baertl1·······1
Pamela Kalning, Matthias Miller, Karin Zimmermann (Heidelberg catalogue 2014)1······1·
Paolo Rosson1·······1
Simon Klee1·······1
Vals AI1·······1
Wacker1······1·
Woodard1······1·

The project lead’s row splits the 302 own targets by outcome. The 69 outside solutions checked and filed here are counted under their contributors, not in that row.

Direct contributions by month

42Sep 2026
91Oct 2026

02 Contributions in detail

Each contributor with every target they are credited on, and for what. An earlier solution that was never published is marked as unpublished and is credited only with the solver’s agreement.

Daniel Bourdeau

Runs the project: chose and checked the targets, directed the work with Claude, and built and maintains the website and the ledger.

project lead · 302 of the project’s own targets: key recovered here ×73 · read with an outside key or decipherment ×143 · not solved ×62 · not applicable ×24 · besides these, 69 outside solutions checked and filed · all write-ups → · the project’s share

George Lasry

Cryptanalyst (DECODE, CrypTool); co-author of the LLM paper; many keys on DECODE and in Tomokiyo's GL.htm; unpublished solutions shared privately.

solution ×59 · verification · key or decipherment used ×34 · earlier solution ×12 · transcription · pointer to a source ×6 · their write-ups →

101 more

Satoshi Tomokiyo

Cryptiana: the catalogue of unsolved historical ciphers most targets come from, and many published keys and overlays.

key or decipherment used ×34 · earlier solution ×7 · transcription ×16 · identification ×3 · pointer to a source ×15 · their write-ups →

62 more

Arya Sanketbhai Patel @aryasn2026 @arya1515

solution ×8 · their write-ups →

Feyseel Nur @Feyseel

solution ×2 · new cipher with solution ×3 · verification · key corrected · transcription · their write-ups →

Norbert Biermann

key or decipherment used ×4 · earlier solution ×2 · transcription · pointer to a source · their write-ups →

WAINUT @LcCompany

A Dutch AI company; pull requests from the LcCompany account, work done with Claude Opus 5.5 subagents.

solution · verification ×3 · transcription · their write-ups →

Nils Kopal

key or decipherment used ×2 · earlier solution ×2 · their write-ups →

Juan Carlos Galende Díaz

key or decipherment used ×2 · identification · their write-ups →

Mírka

Key spreadsheets on DECODE records.

key or decipherment used · earlier solution · pointer to a source · their write-ups →

Thomas Bosbach

Cipherbrain commenter; Catokwacopa DYING DECLARATION; Charles I 1648 nomenclator with Biermann and Brown.

key or decipherment used ×2 · earlier solution · their write-ups →

Wanruo Luo

key or decipherment used · earlier solution ×2 · their write-ups →

Satoru

satoru.net; worked with Claude Opus 5.5.

solution · identification · pointer to a source · their write-ups →

Larry Beck @larrycbeck

solution ×2 · their write-ups →

Richard Bean @RichardBean

key or decipherment used · transcription · pointer to a source · their write-ups →

Paolo Bonavoglia

key or decipherment used ×2 · their write-ups →

Adam Wright

pointer to a source · their write-ups →

  • Burghley to Walsingham, 29 January 1573 — pointer to a source: pointed to the Folger 'Elizabethan Court Day by Day, 1573' summary of this letter (after Read 1960), which identified the cover-names (Davison = Maisonfleur, Hall = the Queen, Glasgow and [9] = Alençon, La Mole)

03 The project

The rest of the work is the project’s own: Daniel Bourdeau chose and checked the targets, and the transcription, cryptanalysis and write-ups were done with Anthropic’s Claude models in Claude Code (claude-opus-5, claude-opus-5-5, chatgpt-astra-6, claude-fable-5-1). Of 386 profiled targets, 302 are the project’s own results, and 73 of them recovered a key by cryptanalysis. 84 targets came wholly or partly from outside contributors and are marked as such: they are left out of the LLM-performance figures. The project’s share is not ranked above: the table is for contributors.

04 What the work builds on

Keys and decipherments made at the time, earlier editions, and the databases the images and records come from. Most targets were taken from Satoshi Tomokiyo’s catalogue, Elonka Dunin’s list and Klaus Schmeh’s Top 50; a listing alone is not counted as a credit.

SourceTargets
Contemporary key or decipherment A key sheet, decipherment or clear copy made at the time (chancery, deciphering office, the recipient's secretary), found in the archive.156
DECODE database The DECODE database of historical ciphers (Megyesi et al.): images, transcriptions and keys contributed by many people.7
Patrick Forbes 6
Gustav Adolph Bergenroth 6
Aloys Meister 3
Étienne Bazeries 3
William K. Boyd 3
Jules Berger de Xivrey Recueil des lettres missives de Henri IV (1843-76).2
Arthur Clifford Editor, The State Papers and Letters of Sir Ralph Sadler (Edinburgh 1809).2
J. S. Brewer 2
L. Didier Editor of Lettres et négociations de Claude de Mondoucet (1891-92).1
Claudio Pérez Gredilla Head of the Simancas archive; his 19th-century decipherment printed by Danvila (Memorial Histórico Español 38, 1899).1
Th. Bussemaker BMHG 27 (1906): Dutch summaries with verbatim French sentences of d'Affry's intercepted letters.1
Ezechiel Foxcroft The Hermetick Romance (1690), English translation of the Chymische Hochzeit with its inscriptions in clear.1
Gilbert Parke Editor, Letters and Correspondence of Bolingbroke (1798).1
Pascual de Gayangos and Vicente de la Fuente Cartas de los secretarios del cardenal Cisneros (Madrid 1875), printed from the 1849 Simancas decipherment.1
Iván Nagy and Albert Nyáry Magyar Diplomácziai Emlékek Mátyás király korából I-IV (1875-78).1
Albert Berzeviczy Aragoniai Beatrix magyar királyné életére vonatkozó okiratok (1914).1
Sebastián Puig y Puig Pedro de Luna, último papa de Aviñón (Barcelona 1920): deciphered Benedict XIII's cipher letters.1
Joachim Le Grand 1
V.-L. Bourrilly and P. de Vaissière 1
Rémy Scheurer 1
Founders Online (The Papers of James Madison) 1
Gabbrielli (Archivio di Stato di Firenze, Chiavi delle cifre, 1863-64) 1
Wilhelm Wattenbach 1
Herman Theodoor Colenbrander 1
Christoph von Rommel 1
Giuseppe Mazzatinti 1
Worthington Chauncey Ford 1
Joseph Stevenson 1
Vilmos Fraknói 1
Politische Correspondenz Friedrichs des Grossen Berlin edition of Frederick II's political correspondence (1879-); prints the minutes of ciphered letters.1
Colección de documentos inéditos para la historia de España (CODOIN) Madrid, 1842-95; prints Spanish state papers, ciphered passages from the secretariat's decipherments.1
Hans Kiewning Editor of Nuntiaturberichte aus Deutschland IV, Nuntiatur des Pallotto (1895-97).1
J. A. Sillem Biographer of Dirk van Hogendorp (1890).1
Gustave Baguenault de Puchesse 1
Uppsala University Library (C collection catalogue) 1
Royall Tyler 1
Denis-Louis-Martial Avenel 1
Joseph Bain 1
Jean Lestocquoy 1
Albert Büchi 1
Traugott Schiess 1
Sheila R. Richards Secret Writing in the Public Records (HMSO 1974), cited by Lasry as Secret Writings (1973).1
G. G. Butler The Edmondes Papers (Roxburghe Club, 1913).1
Thomas Birch A Collection of the State Papers of John Thurloe (1742).1
Zhongshan Warship Museum 1

05 Waiting for an independent check

127 readings whose key was recovered or matched here and that no one outside the project has checked yet. A check means taking the images and the key on the write-up, deciphering a passage independently, and reporting what agrees and what does not. It is the most useful contribution after a solution; how to send one.