Solved: the Rabenhaupt Cipher and Another Maximillian II Cipher

The Rabenhaupt cipher (1646), which has resisted codebreakning efforts for some years, was finally solved by finding the key in the archives. The result is now published by a paper of Eugen Antal, Pavol Zajac, Jakub Mírka in HistoCrypt 2021. See "Some German Ciphers: 1540-1815".

The same proceedings also include a report of a preliminary decipherment of letters to Emperor Maximilian II (1574, 1575) by Nils Kopal, Michelle Waldispühl ("Habsburg Codes and Ciphers") as well as other interesting findings mentioned yesterday and the day before yesterday and more.

Cipher Letter of French Ambassador Published by the Prince of Orange (1684) Identified and Verified

One of my favourite historical characters is William III, Prince of Orange, as I wrote before. When I encountered a cipher used by Comte d'Avaux, French ambassador in the Hague, some months ago (see here), I remembered an episode that the Prince published d'Avaux's letter that was intercepted and deciphered, and I wanted to inspect the original some day.
To my pleasant surprise, it was done by George Lasry. He conducted codebreaking of a ciphertext found in the Dutch Royal Archives, and when some plaintext was revealed, found that it was this famous letter. He verified that the decipherment published by the Dutch was correct, disproving d'Avaux's claim that the Prince deliberately distorted it for propaganda. This result is now mentioned in Section (1C) in "French Ciphers during the Reign of Louis XIV".

Polish Codebreaking as part of UNESCO Memory of the World

I learned that documents including Polish codebreaking activities was added to the UNESCO Memory of the World register in 2018 in Marek Grajek, "Documents of Polish-Soviet War of 1919-1920 Codebreaking" in HistoCrypt 2021 (pdf) (p.64). The official title is "Documents of Polish radio intelligence from the period of the Battle of Warsaw in 1920." The official recommendation explains "The documents of Polish radio intelligence of the Battle of Warsaw are one of the first testimonies to the use of radio monitoring and of new methods of deciphering e enemies' codes. lt was also the Battle of Warsaw here the radio monitoring and those new deciphering techniques played a role that determined the outcome of the battle."
I wonder whether there are other examples where codebreaking is registered as Memory of the World.

The above article interests me for another reason. The codebreaking activities were led by Jan Kowalewski, who taught cryptology to Japanese military officers (in 1923). I didn't know the episode of his first codebreaking in 1919:
"One of the officers of the emerging cipher service of the Polish Army wished to dance at his sister's wedding and asked a colleague for replacement at the night duty. Lieutenant Jan Kowalewski had no previous experience with the ciphers or the codebreaking, but his perfect knowledge of Russian language plus common sense permitted him to break the cipher before the morning. Kowalewski was immediately transferred to the cipher section of the General Staff, where during the following months he managed to organize an effective and efficient codebreaking service." (p.63)

By the way, Kowalewski's job was facilitated by a key the Soviet lost to the enemy, which revealed common features of the Soviet cipher used at the time (p.68). I think it was the one provided by the Japanese military to Poland (see David Kahn, The Reader of Gentlemen's Mail, p.86).

Ciphers for Military Correspondence in the 1640s in BnF NAF 1045

BnF NAF 1045 includes ciphers for military correspondence of Turenne and others. I inspected the first 20 folios out of 57, and described it in "Ciphers Early in the Reign of Louis XIV".

Three More Unsolved Letters of Catherine de Medicis, Charles IX, and Henry III

I was made aware of three undeciphered letters in the 1560s-1570s by Cipherbrain: one from Catherine de Medicis to Philibert du Croc, ambassador in Scotland (1567), one from Charles IX to Philibert du Croc, and one from Villeroi to Henry III (1577). I made references to these in "Unsolved Historical Ciphers" and "French ciphers during the Reigns of Charles IX and Henry III". 

Note (20 September 2021): The following is my preliminary assignment of symbols in Villeroi's letter. It was derived from the few plaintext written between the lines. It can recover some meaning text such as "tout cest" or "aurons tout", but I cannot yet derive further meaningful text from these.

 

 

Another Cipher Letter from Charles I at the Isle of Wight

Cipher letters of King Charles I, executed by the Parliamentarians in 1649, continue to attract attention. The other day, the King's letters of September to November 1648 to Prince Charles during his captivity in the Isle of Wight were deciphered by Norbert Biermann and Matthew Brown (see "What It Takes to Break Charles I's Cipher Used in the Isle of Wight").
Now, I came across a record of another cipher letter of Charles I from the same period. It is a copy of a cipher letter from Charles I at Newport to the Duke of Ormonde dated 28 October 1648, preserved in Northumberland Archives. I have not seen it and does not even know whether it is deciphered. At least, I added a reference to this in "King Charles I's Ciphers".

Solution of Encoded Telegrams of First Prime Minister of Canada

I learned at Cipherbrain that telegrams from John A. Macdonald, the first prime minister of Canada, were solved by Matthew Brown. He knew that the Canadian government used a codebook by Slater, but unlike other telegraph codebooks, decoding is not a straightforward table lookup with Slater's code. Specifically, Slater's code involves translating a word into a number and, after some manipulation of the number, translating it back into a different word. Brown succeeded in identifying the key for the manipulation (addition) by running a computer program to check every possibility.
I added a section of this achievement in "How to Break a Code (Not a Cipher)". I also made related changes in "Nonsecret Code: An Overview of Early Telegraph Codes" and "Unsolved Historical Ciphers".

A Cipher Disk and Treatise on Cipher from ca.1590-1650

I uploaded a new article, "Brûlart de Léon's Cipher Disk and Treatise on Cipher" at Academia.edu. I got interested in the image of a cipher disk included in BnF fr.17538, and found that the volume also includes a treatise on cipher that describes many cipher schemes.
To me, ciphers with a double meaning are the most interesting. (I found Pascal's reference to "cipher" the other day when searching for "chiffre a double sens".)
Some schemes are similar to Francis Bacon's biliteral cipher. At first, I was thrilled, thinking that I might have discovered a work that anticipated Bacon's idea. But similar ideas (triliteral cipher etc.) had already been described by Porta and Vigenère.
I also uploaded a draft version in Japanese.

"Cipher" mentioned in the Pensées de Blaise de Pascal

I uploaded a small article, ""Cipher" mentioned in the Pensées de Blaise de Pascal".
It is a collection of some references to "cipher" in an English translation of Pascal's Pensees. Although it is not a cipher in the cryptologic sense, I included this in my website so that other people do not need to check again.

Struggling for Cryptiana on Smartphones

I bought my first smartphone the other day.
I found that my pages in Cryptiana leave much to be desired for viewing on small screens of smartphones efficiently.
I made some changes in the CSS stylesheet by using "media screen" options, but have not been successful in obtaining the resuls I planned.
Please be patient until my pages get tuned for viewing on Smartphones.

Transcoding of Message in Code by Napoleon's General (1812)

I read of a partially enciphered letter addressed to Napoleon's general during the Peninsular Campaign (Cipherbrain). It is a dispatch of Clarke, Minister of War in Paris, to General Caffarelli in Spain dated 19 October 1812. Karsten Hansky acquired it at an auction site and described it in "A dispatch from the French Minister of War Clarke to General Caffarelli, the commander of the Northern Army in Spain, from the year 1812" (17.06.2021) (pdf).
The passages in code are short, but the plaintext is attached. The code in use is what wac called "Great Paris Cipher" by the British (see also my article "Great Ciphers of Napoleon's Grande Armée"). It is code table #24 in the archives of the SHD (Service Historique de la Défense) in Vincenne (SHD box 1M-2352).
What is interesting to me is the marginal note including the coded message (apparently) transcoded into another code (#29). From the range of numbers, the code #29 appears to have about the same size as #24, but the number of codegroups is different (that is, there is no one-to-one correspondence between the code groups.)

More Cipher Letters of Le Tellier

I added references to more letters from Le Tellier's correspondence in "Ciphers Early in the Reign of Louis XIV". They are found in BnF fr.6884, fr.6889, and fr.6891.
I have already reported that the correspondence between Le Tellier and Colbert appears to have switched to two-part code (Le Tellier-Colbert Cipher 2 (DE=13/59~)) between November and December 1650 (though the arrangement is not completely random), and Mazarin also used it in 1650. This time, it was found DE=13/59~ was used by Mazarin as late as December 1652, while Le Tellier-Colber correspondence used a different two-part code (Le Tellier-Colbert Cipher 3 (DE=18^)) in January 1652.

Codebreaking through Comparison of Two Independently Enciphered Texts

I uploaded a new article "Codebreaking through Comparison of Two Independently Enciphered Texts", which presents my solution of a cipher used in a letter from Abel Servien to Melchior de Sabran (1632). It was quite simple a job, because some words in the clear gave a clue. More interesting would be the very comparison of the two independently enciphered ciphertexts.
I also added references to unsolved ciphers in Sabran's letters in "French Ciphers during the Reign of Louis XIII" and "Unsolved Historical Ciphers."

 

 

Colbert de Croissy Switched to Numerical Cipher in Italy, but Reverted to Figures with Diacritics in London

I made several additions, mainly related to Colbert, to "Ciphers Early in the Reign of Louis XIV" and "French Ciphers during the Reign of Louis XIII" from the Baluze collection in BnF. In this update, the most interesting is the changes of ciphers used by Colbert de Croissy. He used cipher consisting of figures with diacritics, typical in French ciphers at the time, in 1659 (DE=28) and 1660 (DE=42~) when he was Intendant of Alsace. But he switched to a purely numerical cipher (1660-1661) during his mission to Rome (DE=91). He used another numerical cipher in Cleves in 1666 (DE=151), but reverted to figures with diacritics (1668-1674) in his London embassy (DE=68). Somehow, specimens of purely numerical ciphers in France are often related to Italy.

A Cipher between Cardinal Mazarin and Anne d'Autriche

I added a section "Mazarin-Anne d'Autriche Cipher (1651)" in "Cardinal Mazarin and Ciphers". Although the nomenclature of the cipher is printed in Ravenel (1836), the substitution alphabet is not included therein. I reconstructed the substitution cipher by comparing the manuscript letters and the version printed in Ravenel (1836). (Though Ravenel suggests the manuscript key is extant, I could not find it online.)

Cardinal Mazarin Used Partially Two-Part Code

When I posted "Cardinal Mazarin and Ciphers", I thought Mazarin's letters in cipher would not be available online (this is why the article is not titled "Cardinal Mazarin's Ciphers") and thought his cipher might be little more than a short nomenclature, judging from a specimen printed in Ravenel (1836).
Contrary to my expectations, I found a specimen that shows Mazarin('s secretary) used two-part code in June 1651 during his exile in Germany (though the arrangement is not completely random). It is the same cipher as the one used between Le Tellier and Colbert in December 1650. At present, I think the Le Tellier-Colbert cipher was given to Mazarin, who went to exile in Germany, rather than Le Tellier and Colbert were using the cipher given by Mazarin. More specimens are necessary to make a call.
I now added a section "Mazarin's Cipher" to describe these findings.

Note (16 October 2021): The original title of this post was "Cardinal Mazarin Used Two-Part Code." Although I included a reservation "the arrangement is not completely random" in the body, I thought I should add "Partially" in the headline, too (see today's post).

Charles I's Letters from the Isle of Wight Broken after Centuries

Some years ago, I presented three letters in cipher from Charles I to Prince Charles and another to Mr. Worsley in "King Charles II's Ciphers during Exile" and also included them in the list in "Unsolved Historical Ciphers". When Klaus Schmeh and Elonka Dunin chose them as one of the topics in their webinar, they found additional materials in the archives, which allowed Norbert Biermann and Matthew Brown to solve the cipher used in two of the four letters in my list. I presented their achievement in "What It Takes to Break Charles I's Cipher Used in the Isle of Wight".

Ciphers in Colbert's Correspondence

I reconstructed about dozen ciphers from Melanges de Colbert 101-176, and put them in a new section in "Ciphers Early in the Reign of Louis XIV". It is noted that Colbert did not use two-part code in the correspondence in this series (1659-1674), though he once used Le Tellier's two-part code in 1650 as I reported the other day.
There are three undeciphered ciphertexts (relatively short), which I put in a new section "Colbert Correspondence (1665, 1673, 1674)" in "Unsolved Historical Ciphers".

Misplaced? English Cipher Letter in French Archives

The cipher of a wholly enciphered letter in BnF fr.2988, f.1, was broken by Torbjörn Andersson in 2017. Unexpectedly, the plaintext turned out to be English. The recipient is called "your ...", and an obvious candidate is "your Majesty" (Henry VIII). Such an identification is supported by references to "your realm" in the text. But the text also refers to "your son". Although Henry VIII famously lacked a son until 1537, I noticed that he had a bastard son known as Henry FitzRoy.
I posted my decipherment in a new article "Misplaced? English Cipher Letter in French Archives" to help historians to identify the nature of this letter.

Another reason of this post is its possible relation to another undeciphered ciphertext signed Hieronimo Ranzo on the following folio (see "Venetian Ciphers with Superscripts"). Since f.1 and f.2 are treated as one item in catalog information, I wondered whether one is an enclosure of the other. But at least the decipherment of f.1 does not appear to refer to an enclosure.

A Cipher Delivered to Charles I by Mazarin's Ambassador

When Charles I of England was under close watch of the parliamentarians in Holdemby in 1647, some communication with the outside was conducted clandestinely. When searching for Cardinal Mazarin's cipher, I came to know that Mazarin bade Bellievre to obtain a peace between the King and the parliament, and the latter even managed to deliver a cipher to the King.
I added this episode to "King Charles I's Ciphers".