972Unsolved Historical Ciphers
Republished copy of Daniel Bourdeau’s Unsolved Historical Ciphers, released under CC BY 4.0. Text unchanged; hosted by JIC alongside its translations; not an official copy by the author · View the original ↗
le Roi d'Espagne · vient · de nommer · (Parenthesis) M. le Duc de San Carlos (Claudatur)
388 1949 600 477 2395 1800 983 1440 692 1369 267 2506 1801 1949 335 1954 709 1212 958 477 1211 307 2415

Vienna · Staatskanzlei cipher office · memorandum in clear German · 1 July 1816

Loeschner's memorandum on the cipher instruction

ÖStA, Haus-, Hof- und Staatsarchiv, Staatskanzlei Interiora, Chiffrenschlüssel Kt. 20, alt. Fasc. ad 27, ff. 30–40 · DECODE R2227, catalogued as a letter "with short encrypted parts" from "W. Loeschnen?" to an unknown recipient, with no decipherment recorded

The document is a memorandum in clear German on how the ministry's cipher keys should be used. Every figure in it is a worked example with its plaintext written above it, so there is nothing to decipher. It was identified here from its heading and signature.

Daniel Bourdeau · posted · updated

Method: not a cipher

Summary. DECODE R2227 (20 pages, numerical, "Letter with short encrypted parts", no decipherment recorded) entered the project catalogue as a ciphered letter of "W. Loeschnen?" to an unknown recipient, dated 1 July 1816. All eleven openings were viewed here. The document is written in clear German Kurrent. Its heading reads Zusätze und Abänderungen, welche in der Instruktion zum richtigen und zweckmäßigen Gebrauch der in der offiziellen Korrespondenz zwischen den k.k. Missionen und der geheimen Hof- und Staatskanzlei üblichen Ziffernschlüssel gemacht werden dürften. It is signed "Wien am 1ten Julius 1816. W. Loeschner". It comments on a cipher instruction page by page and line by line. The number groups in it are demonstrations, and each one has the French plaintext written over it, for example the announcement that the King of Spain has named the Duke of San Carlos ambassador. Nothing is hidden, so there is nothing to decipher. The item is closed as not a cipher, and a DECODE correction (name, record type and status) is queued.
Opening 9 of R2227: French words written over number groups, le Roi d'Espagne vient de nommer, Parenthesis, M. le Duc de San Carlos, Claudatur
Opening 9: a worked example, with the plaintext above the figures and the Parenthesis and Claudatur signs marked. Image: Österreichisches Staatsarchiv, HHStA, Staatskanzlei Interiora, Chiffrenschlüssel Kt. 20, opening 9, via DECODE R2227.

01 The document

The eleven openings contain one continuous memorandum in a single clerical hand. After the heading, each paragraph cites a place in the instruction it amends: "Seite 2, Spalte 2, Zeile 3 von Unten", "Seite 9, Spalte 2, Zeile 5", "Seite 10, Spalte 2", "Seite 23, nach der Zahl 1918", "Seite 32", "Seite 33, Linie 2 von Unten". It closes with an appendix, Beilage: Ueber den Gebrauch der Doppel- (Supplementar-) Zahlen. The last page carries the date and the signature, W. Loeschner. DECODE's "Loeschnen?" misreads the final letter. Among the topics:

02 Why there is nothing to decipher

The figures occur only inside examples. On opening 9 the plaintext le Roi d'Espagne vient de nommer (Parenthesis) M. le Duc de San Carlos (Claudatur) son Amb.r &c is written directly above its code groups, 388 1949 600 477 2395 1800 983 1440 692 1369 267 2506 1801 1949 335 1954 709 1212 958 477 1211 307 2415, with ⊖ marks for the word divisions. Opening 5 has a short table of the same kind (A, B and syllables against four-digit numbers). Opening 3 shows syllable splits such as "Com-pa-ra-tion". Every one of these examples comes with its plaintext. The memorandum describes a key but does not contain one, and it hides no message.

03 What stays open

Nothing on the cipher side. The memorandum was not transcribed in full. It is a useful source for Austrian cipher-office practice around 1816, and the numeric examples could be checked against the Staatskanzlei keys of that period on DECODE. For DECODE, the queued correction asks for the author to be changed to W. Loeschner, the record to be described as an instruction memorandum, and its decryption status to be set to not applicable.

04 Sources

Notes and profile: targets/loeschnen1816/.