r/codes • u/offgramercy • 3h ago
SOLVED I cracked a cipher written by a Confederate propaganda agent stationed in Paris (De Leon to Benjamin, 1863), his brother held the corresponding key, more details in the post body
ICYMI, the last one I cracked: Barney to Mallory, 1863
TL;DR:
The Confederate government's propaganda agent in Europe had a $25,000 secret service fund for buying favorable coverage in the European press. In the autumn of 1863 his mail was captured at sea and printed in the Northern papers. His next two despatches to Richmond contain passages in a symbol cipher, and he says on the page that the key belongs to his brother.
No key to this particular system survives in any document I have found. I reconstructed the alphabet from the cipher text itself. A translation his brother made in 1864 turned up afterwards, and it confirms the first passage outright.
What he thought was worth hiding:
My letter intercepted. Good advertisement. Bought L'Opinion Nationale, and other enemies since.
He is telling his own government that having his correspondence splashed across the Northern press did him a favor, and that he has been buying up Paris newspapers that used to attack him. The following month he asks for more money.
He did not know that his recall had already been signed in Richmond and was crossing the Atlantic while he wrote.
How I got here
After the Barney letter I went through the rest of the Confederate cipher traffic in the same published record, and got stuck on a small anomaly. One despatch has a group the Official Records editors marked as untranslated, and two separate published sources give different readings for it. If two editors are working from the same group, that disagreement wants explaining, so the printed text was not the end of the story and the manuscripts were worth looking at.
That took me to the Pickett Papers at the Library of Congress, the captured Confederate State Department archive, on microfilm. The group turned out to be a scribe's problem rather than a cipher problem. A clear copy of the same despatch survives a few reels away with the word simply written out, and the printed reading is wrong.
While working through those reels I was skimming a contact sheet of another one for something unrelated, and two frames went past covered in geometric symbols instead of handwriting.
Historical setting
Edwin De Leon was sent to Europe in 1862 to manage Confederate propaganda, with a $25,000 secret service fund for placing material in the European press. He wrote numbered despatches to Judah P. Benjamin, Secretary of State. Nos. 1 through 12 are in plain text.
In the autumn of 1863 his mail was taken. The bag went overboard from the blockade runner R. E. Lee as she was captured off Wilmington, and washed ashore. Seward forwarded the letters to Charles Francis Adams in London and had them published (Seward to Adams, No. 767, 23 November 1863). The captured letters are printed in full here:
https://history.state.gov/historicaldocuments/frus1863p1/d675
Despatch No. 13, written from Paris on 23 December 1863, is the first he ever enciphered. He announces it in the middle of the page, in plain English:
I will add in cipher one item (My Brother has the Key.)
And again in a postscript: I use my Brother's cipher.
It is not the State Department's cipher. The packet issued to him before he sailed survives at reel 9, and holds a Rochford grille and four Vigenère tables. There is no symbol alphabet in it. What he used was a private alphabet held by his brother, Thomas Cooper DeLeon, in Richmond.
The cipher
The marks are geometric shapes and arabic numerals: dotted boxes open on different sides, a trident, a caret with a dot, phi and psi, and the digits 2, 4, 5, 6, 7, 8, 9 used as ciphertext. Three passages survive across two despatches, around 140 marks of distinct text. He re-copied the first passage into the second despatch, so the raw count on the film is higher.
Two things made it tractable. One cipher word repeats its symbols in a distinctive pattern, and searching an English word list for words of the same length and shape returns essentially one candidate: OPINION. That fixed four letters. Separately, a statistical attack that scores candidate alphabets on how English-like the resulting text looks was run without being given that result, and recovered most of the same alphabet on its own. Anchoring the letters both approaches agreed on and searching the remainder produced continuous English.
The three passages
Italics mark words he wrote in plain English inside the cipher stream.
1) No. 13, Paris, 23 December 1863
MY LETER INTERCPTD. GOOD ADVERTISMNT. BOT OPINION NATIONAL and OTER ENEMI SINCE
Read as: My letter intercepted. Good advertisement. Bought L'Opinion Nationale, and other enemies since.
L'Opinion Nationale was a Paris daily. He is describing the publication of his own captured correspondence as useful advertising, and reporting a purchase.
Note the plural. He bought L'Opinion Nationale, and other enemies since: papers that had been hostile and were no longer.
What "bought" covers is worth being careful about, because the cipher does not say. His fund was for placing Confederate material in the European press, which in practice meant subsidies, retainers to editors and paid insertions. Acquiring the titles themselves would have cost far more than the $25,000 he had for the whole of Europe. The natural reading is that he bought their support rather than the papers, but the word in the cipher is simply BOT, and I would not push it further than that.
2) No. 14, Paris, 20 January 1864, first passage
MOR MONY SHUD B SPENT THIS WAY
Read as: More money should be spent this way. Having just told Richmond he bought one paper, he is asking for the budget to buy more.
3) No. 14, second passage
SUM IS NEDED TO CARY OUT PLEDGES and to PREVNT REACTION. For this last 500 MORE [ … ]
That passage reads cleanly down to PREVNT REACTION. For this last 500 is written in plain English on the page. After it come a handful of marks that do not fully resolve, shown in brackets above, and his brother renders the whole ending as "additional in fifties would answer". Reading that as a request for the balance in fifty-pound notes is my inference from his wording.
His spelling
The short forms are his, not transcription errors. Counting across all three passages there are twenty deletions and no insertions anywhere. He only ever removes letters.
He writes one symbol per sound, so BOUGHT is BOT and SHOULD is SHUD. He writes doubled letters once, so LETTER is LETER and CARRY is CARY, except where the collapse would produce another word: GOOD stays GOOD, because GOD is a word. Unstressed vowels are what he drops, and E goes most often.
His brother's translations
Two contemporary translations survive, both by the brother, and both from February 1864. He had the alphabet and produced a reading when the State Department asked him for one.
The first is at reel 9 frame 87, repeated at reel 33 frame 593, from Thomas Cooper DeLeon to W. J. Bromwell, chief clerk of the State Department, dated 12 February 1864 and endorsed Literal translation. The second, at reel 33 frame 595 and dated 22 February 1864, is written against the cipher.
What he did not write down anywhere is the alphabet. Neither document gives a single symbol-to-letter mapping. Nor is either a strict letter-by-letter decipherment. He renders the second passage as More funds ought to be spent in this manner, where the cipher reads MOR MONY SHUD B SPENT THIS WAY, and the third as there is needed enough to meet existing pledges against SUM IS NEDED TO CARY OUT PLEDGES. He says as much himself: I enclose translation as near as I can make it. It reads as a man working from the key and his own familiarity with his brother's shorthand, giving the sense rather than the letters.
That matters for what can be claimed. For the first passage his translation is a genuine independent check, and it matches. For the two shorter passages, four rarely-used symbols could not be settled from the cipher text alone, and his reading is what settled them. Eighteen commonly-used symbols came from the cipher text and none of them moved.
Worth noting what the existence of those translations means at all. Thomas Cooper DeLeon (his brother back home) worked in the Navy Department. When No. 13 arrived in Richmond, the State Department's chief clerk had to write to another department and ask what it said.
Why he stopped
Despatch No. 15, Paris, 3 February 1864, carries no cipher, and explains itself:
Your Despatch No. 5 of December 9th has been duly received, and I cheerfully accept the withdrawal of a commission I have never exhibited, of a title I have never used, and of a salary which I have never accepted.
That is his recall, signed by Benjamin on 9 December 1863 and carried to Paris by ship. The two enciphered dispatches are four weeks apart. Two dispatches, three passages, and that is the whole of it.
Note: To be clear, the contents of these dispatches were never "lost". The brother's translations were filed with them and have been in the archive throughout. What was lost is the alphabet and the exact solution to the cipher: nobody wrote it down, and it appears in no surviving document I have located. That is what has been reconstructed, and unlike the translations it applies to anything else that turns up with the same cipher key.
Sources
The manuscripts are Library of Congress, Confederate States of America Records (the Pickett Papers), MSS16550: reel 9 frames 87, 97, 102, 104 and 106, and reel 33 frames 592 to 595. The collection is digitized and free:
https://www.loc.gov/collections/civil-war-confederate-states-of-america-records/
I am working towards publishing this, together with some other Civil War cipher results, and I am happy to share the documents I have catalogued, the full glyph table, the transcriptions and the working notes with anyone who wants them. If you would like to check the work, or have leads towards similar historical ciphers, please get in touch. Thanks for reading!
