[12] · REFERENCE

Sources & gallery

Everything I read, the images with their licences, and my own working material.

What I read

Primary research

source	what is in it
Hauer et al., HistoCrypt 2021 (PDF)	Substitution solvers, language identification over 380 languages, a text-vs-music classifier. Concludes: not a simple monoalphabetic substitution of English; probably language, not music; probably not a hoax. I kept an extracted copy for reference while building the lab.
Wase, Dorabella unMASCed, Cryptologia 2023	Establishes a baseline first: solvers hit 98.7% on English and 98.6% on Latin at 87 characters, then fail here. The cleanest negative result in the literature — and the one my matched-effort run reproduces.
Dorabella Cipher as Musical Inspiration (arXiv)	The music-hypothesis line of argument.

Reference

source	what is in it
Wikipedia — Dorabella Cipher	Line lengths, symbol set, claimed solutions, image scans.
Wikipedia — Edward Elgar	Biography.
Wikipedia — Enigma Variations	The friendship map: all fourteen dedicatees.
Wikipedia — Nihilist cipher	How the cipher Elgar broke in 1896 works.
The Cipher Foundation	The “3 versions each of 8 rotated E-shapes” reading, and the key applied to the note — the `BLTACE…` string my transcription is validated against.
Dora M. Powell (née Penny), Edward Elgar: Memories of a Variation, 1937	The memoir that preserved the cipher after the original was lost.

Ongoing investigation

source	what is in it
Cipher Mysteries — Dorabella index	Nick Pelling's running coverage; the most consistently sceptical source.
Cipher Mysteries — Elgar's other ciphertexts	The Liszt fragment, the Courage cards, the 1920s notebook, and the known plaintexts.
Cipher Mysteries — 2025 update	The Bartlett and Menkins claims; the Royal College of Music diaries plan.
benzedrine.ch — clues or red herrings	An alternative 24-symbol key and transcription, plus structural observations — and the same naming convention as mine (a glyph is named by its open side).
Robert Padgett — Elgar's Enigma Theme Unmasked	The contested maximal reading of the Variations, and cleartext tables for Dorabella.

Context and colour

source	what is in it
Eric Sams — Elgar's Cipher Letter to Dorabella	The 1970 Musical Times attempt, from the author's own archive.
Nautilus — The Artist of the Unbreakable Code	The Schooling challenge and Elgar's personality (not the box, the cards or the notebooks).
Schneier on Security — Edward Elgar's Ciphers	A short overview from a cryptographer.

Where sources conflict — Dora's age, the date of the Liszt fragment, Gazette or Magazine, box or floor — the conflict is stated on the page concerned rather than silently resolved.

Texts behind the language models

Public-domain books from Project Gutenberg. Only the packed n-gram tables were used by the tools, not the books.

German — 2.5 M letters

Goethe, Die Leiden des jungen Werther (epistolary, 1774)
Fontane, Effi Briest (1895)
Mann, Buddenbrooks (1901)
Kafka, Die Verwandlung (1915)
Nietzsche, Also sprach Zarathustra (1883)
Goethe, Faust I (1808)

Chosen to lean towards letters and domestic prose where possible; umlauts folded (ä → ae) the way a period English reader would transliterate them.

Period correspondence — 3 M letters

Collingwood, Life and Letters of Lewis Carroll (1898)
Letters of Charles Dickens, vols 1–3
George Eliot's Life, as Related in Her Letters, vols 1–3
Life and Letters of Charles Darwin, vol 1
The Letters of Jane Austen
Letters of John Keats to His Family and Friends
Business Correspondence, vol 1 · Crowther, How to Write Letters · The Gentleman's Model Letter-writer · The New Century Standard Letter-Writer
Lorimer, Letters from a Self-Made Merchant to His Son · Chesterfield, Letters to His Son

Filtered to the sentences that read like correspondence — first and second person, direct address — dropping the biographers' narration.

Document gallery

Images from Wikimedia Commons, each with its licence and author. Files marked link are not copied here — follow the link to see them on Commons.

The Dorabella note — **Dorabella-cipher-image.png** — the note, 1897. Public domain · Edward Elgar · source page

Symbol set table — **DoraBella Cipher Symbol Set** — the 24 symbols with their letters. CC BY 3.0 · PeterBrooks · source page

Symbol set table, smaller — **DoraBella Cipher Symbol Set, smaller** — the same table at a smaller size. CC BY 3.0 · PeterBrooks · source page

Circle diagrams M1 to M4 — **DoraBella Cipher related graphics** — the notebook's circle diagrams, numbered M1–M4. CC BY 3.0 · PeterBrooks · source page

**Cleartext with Spanish words highlighted** — peca, y, ir, y, cerre, se, sed, ser. CC BY-SA 4.0 · Robert W. Padgett · source page

**Cleartext with Spanish terms highlighted** — peca, y, ir, y, cerre, se, es, sed, ser. CC BY-SA 4.0 · Robert W. Padgett · source page

Cleartext EDU signature — **Cleartext “EDU” signature** — characters 66–68 read as Elgar's pet name. CC BY-SA 4.0 · Robert W. Padgett · source page

not copied	licence	author
DorabellaCipherElgarFont.png — the orientation of all the symbols	CC BY-SA 4.0	Skaifaya	link
DorabellaKey2.png — the key graphic, avoiding font problems	CC BY-SA 4.0	Skaifaya	link

The 1897 document itself is long out of copyright. Individual scans and derived diagrams are not necessarily — several here are CC BY or CC BY-SA, shown unmodified with attribution, and require attribution if you reuse them. Licence texts: CC BY 3.0 · CC BY-SA 4.0.

My own working images

The note with nine glyphs circled — **The nine undecided glyphs**, circled in my draw.io transcription. [05]

Annotated notebook pages — **The notebook pages with the known messages written in.** [03]

Glyph overlay on a circle diagram — **Glyph shapes traced into one of Elgar's circle diagrams.** [06]

Turning snowflake sketch — **The snowflake key in successive positions.** [06]

Notebook pages — **Elgar's 1920s notebook pages** — public domain.

**The 1886 Crystal Palace programme page** with the marginal fragment — public domain.

Two photos of antique compasses (8/16-point and 32-point cards) were part of my working folder as inspiration for the snowflake idea. They are third-party photographs of unknown licence, so they are described on [06] rather than reproduced; the compass drawing there is my own.

This project's own files

transcription: my draw.io diagram → lab/transcription.py (three readings, the nine ambiguities, five circular corrections)
lab: align, repair, signif (validation) · analysis, structure, run_structure (key-free tests) · solver, run_solve, run_final, run_matched (attacks) · crib, hypotheses, languages, model_prior · holdout, bakeoff, odds (calibration) · crosscheck, rowcheck, snowflake_test (engine proofs)
toolkit: core.js (the polar-key engine) · ui.js (glyph rendering) · score.js (models, annealer, statistics) · search.js, sweep.js (key hunts) · recipe.js, session.js · transpose.js, strops.js
hunt: server/dorabella_hunt.py, run.sh, an Ubuntu installer and systemd units · dashboard/ (status page and server)
on this site: assets/core.js and assets/ui.js are the toolkit's own files, unchanged; toolkit/ holds the built interactive tools

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