A Polyalphabetic Cipher of Mary, Queen of Scots

I added a polyalphabetic cipher used by Mary, Queen of Scots, in "Ciphers of Mary, Queen of Scots". (I learned of this cipher from Oliver Storz.) It was used in September 1568, a few months after Mary fled to England. This is the only polyalphabetic cipher used by Mary known to me.
Another interesting thing in this cipher is that the letter remained unsolved until the twentieth century, when it was solved in the French foreign ministry.

Cipher Letter of Francis II, Husband of Mary, Queen of Scots

I've been completing and uploading updates to some articles that accumulated while coauthoring the paper about Mary, Queen of Scots I reported the other day.
They include a cipher letter of Francis II, husband of Mary, Queen of Scots, addressed to the Bishop of Rennes (now included in "French ciphers during the Reigns of Charles IX and Henry III"). This is the first time I came across a cipher during the short reign of Francis II. (I'm sure there are more in the archives.)
Although it is not deciphered, it uses the same cipher that I reconstructed before from correspondence between the Bishop of Rennes and Catherine de Medicis.

More Ciphers/Letters Related to Mary, Queen of Scots

I reported my coauthored paper about the discovery of Mary Stuart's hitherto unknown letters the other day. I now uploaded "Ciphers of Mary, Queen of Scots". It lists ciphers and ciphertexts related to Mary (previously known ones for the most part). I still have some leads and hope to update it in near future.
Some ciphertexts are not accompanied with plaintext. I identified some of them with known plaintext. There still remain some ciphertext I could not identify, which I added in "Unsolved Historical Ciphers".

(18 February) I added a section for cipher letters related to Mary preserved in The British Library in "Ciphers Mary, Queen of Scots". I could identify most in my list with known plaintexts, and deciphered one by using the same key (Mary's letter to Norfolk in Cotton MS, Caligula C II, f.74).

50+ Letters of Mary, Queen of Scots (1578-1584), Discovered in French Archives

More than fifty letters of Mary, Queen of Scots, preserved in the French national library were found and deciphered by an international team of three cryptographers including me (George Lasry, Norbert Biermann, Satoshi Tomokiyo). The tragic life of Mary is well-known -- after three mariages, she fled to England, where she was held prisoner, and after years of captivity, she was executed on evidence of a deciphered letter for plotting against Queen Elizabeth. The letters discovered are entirely in cipher, with nothing to indicate who wrote them to whom and when. Codebreaking revealed that most (54) of the letters are letters written during 1578-1584 from Mary to Castelnau de La Mauvissière, French ambassador in England. Among them, more than 40 up to the middle of 1583 are hitherto unknown letters and are expected to provide new insights about Mary during her captivity in England.
The results were published in George Lasry, Norbert Biermann, Satoshi Tomokiyo (2023), "Deciphering Mary Stuart's Lost Letters from 1578-1584" in Cryptologia (Open Access) today, that is, 8 February, the anniversary of Mary's death.
I wrote an article in Japanese and a brief introduction in English. George talks on the discovery in a video.

Louis XIII's Mysterious Letter (1635)

There is a letter from Louis XIII, dated 6 April 1635, which is written in the normal alphabet but is full of nonsensical words except for a few French words. (I learned of this from David Chelli and Cipherbrain.) I added this in a section in "French Ciphers during the Reign of Louis XIII".
Here is my provisional transcription:

Mon Cousin, bac racle suroaert brancher
guignanocher rip goelle harpe volduc
hagardement son bac bobe her rabo
en vol baratre her Spir, siron pincer
her lily ser, cest basco rideray son sol
flaih poignart son vol tigre Capitulo
fauche midot siron ficher a vol Stellee
bac alarme a son broche ramo sol trepont
los ridant son taf sol branchoit lily ser
ton vol inquiet her menin citro Capitulo
et son sol abonast holta hillot, cest poursevoir
son pinson duc Chatou, nono los racke ride
a los semsom margot sol me pellera, cest

nen ay tor profite pincer a Astolfe her
gorion her vol soter, circo margot vol
Capitulo pousera verie, cest vol poudreray
fon sol ne bulte a son ferre, ny ne vol
mare son vol moins son sol armera
rip go son nono joute son go Stercol vol
ne me roguette for, cest ne rabo vol
brancheray tor pinson inerne venant
son tost her basco marert midot
tarespant joue cest rodilloraq vol octro
exhalt tour basco brosse en sa croche
Louis
a St germain en laye
ce 6me Auril 1635

Some ideas are proposed in comments to Cipherbrain, but no conclusion is reached.
By the way, Klaus Schmeh announced Cipherbrain will be closed at the end of the year. Cipherbrain manages a very lively community where people from all over the world gather and discuss various ciphers or other related mysteries. I hope some other platform will be found to host his blog.

Emperor Charles V's Letter (1547) Deciphered after 500 Years

A letter from Charles V to Jean de Saint-Mauris, his ambassador in Paris, preserved in Bibliothéques de Nancy, was broken by Cécile Pierrot, Pierrick Gaudry, Paul Zimmermann, and Camille Desenclos (I learned this from George Lasry and from Cipherbrain). Their presentation on 23 November 2022 received a wide media coverage.
As it turned out, the cipher is the same as what I reconstructed (and posted) some years ago from a letter between the ambassador and Granvelle preserved in Spanish archives and called "Granvelle-Saint Mauris Cipher." But it's understandable that the French researchers were not aware of this because I myself didn't realize they are the same until after I drafted a report of this decipherment, which is now included in a section in my article "Ciphers during the Reign of Emperor Charles V".

 

(The image adapted based on an image downloaded from https://galeries.limedia.fr/ark:/31124/dct0sbwx8vmhspk0/ , updated on 13 January 2022))

A Codebook for Encoding Commerce Info into 13 Figures

I acquired a codebook for encoding sentences for commerce into 13 figures. Such a kind of codebook was common during the age of telegraphy (see "Figure Codes and Code Condensers -- Data Compression Before Computer Age"). For this particular codebook, an example 13-digit figure 011230135435 (excepting the 13th check digit) may consist of:
01 We offer you
123 articles (to be agreed between correspondents)
013 to be shipped in January-February in five cases
54 at 0.63 yen (presumably per some agreed unit)
35 This is the best possible offer we can get for it.

As it turned out, this is the same as an attachment in Chapter XL of 山口造酒・白井健次『英文商業通信寶鑑　附十三数字組立暗号電報』（1922）, noted in an article in Japanese.

Deriving a Fake Message from Ciphertext: 16th-century Venetian Example

Suppose you are arrested by the Russian authorities with a letter in cipher which reads: "Down with Putin". Pressed hard to divulge the plaintext, you confess a fake plaintext: "Long Live Putin."
However absurd it may seem, cryptologically, it is quite easy. All you need is the Vigenere cipher with a meaningless key sequence. The Vigenere cipher amounts to an addition: C (ciphertext) = P (plaintext) + K (key). So, given a ciphertext (C) and whatever plaintext you want to reveal (P), you can find a key K = C - P that supports your fake reading.

Such a scheme, called Falso Scontro, was officially adopted in 1587 by the Venetan Republic, according to Paolo Bonavoglia, "The Enigma of Franceschi's Falso Scontro" (HystoCrypt 2022), Section 6. Bonavoglia's interpretation of how it works (Mode 1) is detailed in Section 8.1. (The base cipher may not be the same as Vigenere, but it is not essential.)
1. Alice and Bob somehow agree on a secret key K.
2. Alice enciphers a plaintext P by C = P + K. She also derives a fake key FK to produce a fake plaintext FP from the same ciphertext C: FK = C - FP.
3. Alice sends C and FK to Bob.
4. If the message arrives safely, Bob can use the pre-arranged secret key K to recover the true plaintext: P = C - K. (If Bob is forced to decipher, he can use FK to produce the fake plaintext FP.)
5. When Bob writes back to Alice, he can use FK as the new secret key, and repeat the steps 2-4. (So, the fake key FK, if safely received, also works as a future key.)

Although this is interesting, it appears to have never been used (Section 10).

Connection of Cipher Networks of East and West Germany in 1990

Some months before German Reunification in October 1990, a secure communication channel was established between East Germany (GDR: German Democratic Republic) and West Germany (FRG: Federal Republic of Germany) by using T-310, the most widely used teletype cipher machine in GDR (p.181). This is something I haven't heard (because I know little about modern crypto-history) until I read Winfried Stephan, "Use of T-310 Encryption During German Reunification in 1990" (HystoCrypt 2022).
In May 1990, six months after the fall of the Berlin Wall, the two German states signed a treaty for monetary, economic, and social union, which came into effect in July.
In the meantime, T-310 devices were handed over by the GDR and installed in Marienthal/Ahrweiler in the FRG in June (p.182). They were connected to their counterpart in Prenden in the north of Berlin, thus establishing a secure communication link between the GDR and the FRG (p.183). From these nodes, almost every place could be reached in secure communication in the GDR and the FRG. The amount of telexes exchanged between the two nodes was more than 800 to 900 telexes per day. (p.184)
The link between the two German states employed the East Germany device T-310 probably because it was exclusively used in the GDR, rather than used between member states of the Warsaw Treaty Organization. The device used in the FRG could not be provided to the GDR because of the NATO regulations. (p.184, p.181) (The GDR withdrew from the Warsaw Treaty only in September.)
When a direct connection to the GDR Ministry of the Interior was esbalished, the teletype link between Marienthal and Prenden ceased to operate around mid-August. In the direct link, the NATO cipher device Elcrotel 4 was used (p.184). This was made possible by rapid political developments (p.189). The Reunification Treaty was signed on 31 August, which came into effect on 3 October 1990.

Solution of Catherine of Aragon's Cipher Letter to King Ferdinand

Back in 2018, I reported codebreaking of Catherine of Aragon's letter to King Ferdinand, her father from November 1509. It was achieved by Victor and Thomas Bosbach independently. At the time, I refrained from disclosing the solution because I had submitted it as a challenge to the public at MTC. Although my contact at MTC3 gave me an ok for publishing the results as early as 22 September 2020, I couldn't reconcile the two similar but different solutions to derive the best deciphered text. Now I publish the results, hoping that someone versed in Spanish completes the solution, and, better still, contextualizes the deciphered text.
See: Solution of Ciphertext of Catherine of Aragon to King Ferdinand (1509),

A Batch of Solutions to Unsolved Historical Ciphers by George Lasry

I call for solutions for "Unsolved Historical Ciphers", to which I receive or find solutions from time to time. This time, I received solutions of no less than 10 ciphers from George Lasry, a computer scientist and expert in cryptanalysis, who has solved many historical ciphers (some of which I mentioned). (It seems his solver can readily solve any cipher mainly based on letter-by-letter substitution, even with many homophones.) I updated my records in related articles, and present all of his solutions in this batch in a new article, "Decipherment of Hitherto Unsolved Historical Ciphers (by George Lasry)".

Books Entirely in Cipher or Shorthand

There are books entirely in cipher or shorthand (not fake ones as I reported before).
Charles Dickens' A Christmas Carol was printed in Gregg shorthand in 1918 by The Gregg Publishing Company (Internet Archive). (I learned of this in Elonka Dunin and Klaus Schmeh, Codebreaking, A Practical Guide (2020), p.352.) Except for the front matter and the running head, pages after pages are filled with text in shorthand. Judging from the publisher's name, this appears to have been made for promotion of the Gregg shorthand system.

 

This is about shorthand, not cipher. But there are also books entirely in cipher. Klaus Schmeh's List of Encrypted Books (Cipherbrain) lists more than a hundred such titles. Of these, nos. 00006 (1835; a couple of hundred pages; preserved in British Library, Shelfmark 4783.a.30) and 00007 (1850; 61 pages; preserved in British Library, Shelfmark 944.c.19) are the most interesting for me, because I'm more interested in publications than personal diaries.
The title page of No. 00006 reads as follows:

EBPOB ES LYO UTLUB,
UMGJOML NÝFLOBJOF
LE VYJGY
SONUTOF VOBO UTEMO
UPNJFFJRTO:
ROJMC DUBL LYO SJBFL
ES LYO
FOGBOLF DBOFOBWOP
JM LYO
UFFEGJULJEM
ES
NUJPOM AMJLH UNP ULLUGYNOML.
"Vonon ubo fibemocofl." -- Ofpb. 3.11.
LONDON
M.DCCC.XXXV.

Apart from "London" and the year 1835, all is encrypted.
This is reported in an article titled "A Femail Conspiracy" in The Sydney Morning Herald, 23 April 1869, Page 6 (TROVE) and The Star (Christchurch), 16 June 1869, Page 3 (Papers Past). Both are the same article reprinted from the Pall Mall Gazette. It is not known whether there are other copies than the ones in the British Library.
A 19th-century philologist took interest in this, only to find it is English in cipher rather than any exotic language. The title reads:

Order of the Altar,
Ancient Mysteries
to which
Females were alone
admissible.
Being Part the First
of the
secrets preserved
in the
Association
of
Malden Unity and Attachment.

Charles Dickens' Unsolved Texts in Shorthand

In February 2022, Charles Dickens' letter in shorthand was cracked (for about 60%) (The Dickens Code, Open Culture, The Dickens Project). It remained unsolved for over 150 years (called the Tavistock letter from the letterhead).
I thank D.P.J.A. Scheers, who authored "The Shorthand of Charles Dickens" (Academia.edu) last year, for attracting my attention to this. (He is credited as one of the contributors to the solution (Roll of Honour).) Although shorthand is different from a code/cipher, it is sometimes called as such (a famous example is Samuel Pepys' diary, mentioned in a previous post).

Dickens taught himself shorthand as a teenager. There were many shorthand systems, but what he picked was Gurney's Brachygraphy, one notoriously difficult to master. Struggles with shorthand are mentioned in the semi-autobiographical novel, David Copperfield (Ch. 38) (The Dickens Code). Moreover, Dickens adapted the system as he used it, which added difficulty in reading surviving texts in shorthand left by him.
The 60% solution (pdf) of the Tavistock letter was achieved by contributors around the world in response to a call by the Dickens code project. (Since 40% is still unread, there is still room to make contributions, though the contest is closed.)
There are eleven shorthand texts left by Dickens (Hugo Bowles, "Dickens's Shorthand Manuscripts", Dickens Quarterly, Johns Hopkins University Press, Volume 35, Number 1, March 2018 (Project MUSE). Bowles is a pioneer in this field and authored "Dickens's Shorthand Deciphered by Identifying 'Sydney Smith' Source Text", Notes and Queries 64.4 (2017): 614-17 (which I have not seen). Some unsolved shorthand texts are presented as challenges at The Dickens Code website. One is still open for a few more days!

Re-discovery of Philip II's Cipher with Secretary Escovedo in Antwerp (1577)

I reconstructed a cipher used in a letter from secretary Escovedo to Philip II dated Antwerp, 9 April 1577 (see here). Since the ciphertext is accompanied with an extract of the decipherment, there was little difficulty in the reconstruction. It is the same as the cipher solved by St. Aldegonde, printed in David Kahn's The Codebreakers, p.120. 

 

My Codebreaking Activities

I don't presume to be a codebreaker, but I have done some codebreaking, as reported in "Unsolved Historical Ciphers". Admittedly, most of the ciphers I solved (as opposed to "deciphered" by using already deciphered materials or finding the key) are simple monoalphabetic ciphers. But when I took inventory of my codebreaking activities the other day, I found the following may be somewhat significant.
- Vatican ciphers (1593) with variable length symbols written continuously (see "Identifying Italian ciphers from continuous-figure ciphertexts (1593)" (Cryptologia))
- A Spanish letter to Emperor Charles V (1529) employing symbols with diacritics (see "Codebreaking of a Spanish Cipher with Vowel Indicators")
- Spanish letters from Philip II to ambassador Vargas Mexia in Paris (1578), which, together with three other keys I identified among known ciphers, may allow reading of a whole collection of undecipehred letters (see "Finding the Keys to Philip II's Cipher Letters to Juan de Vargas Mexia
")

Vigenere Introduced Japanese Syllabary to Europe

When I was browsing Vigenere's voluminous book, Traicté des chiffres (1586), in studying the history of reception of the Vigenere cipher some months ago (see here), I found illustration of Japanese characters in the appendx. Vigenere was the first to introduce Japanese syllabary (if not Japanese characters) to Europe. Although I soon found this is known, I described it in a new article, "Vigenere's Introduction of Japanese Characters in Europe". 

 

 

 

"Code" in a Junior High School Entrance Exam

 I noticed a word "code" in a math problem of an entrance examination of Kaisei, a prestigious private junior high school in Tokyo. (I appeared in an ad of a prep school on a newspaper on 6 February 2022.) The following outlines the problem. It is merely about combinations rather than cryptography, as expected.

A code is represented by a 2-by-7 matrix. A filled square cannot be adjacent to another filled square horizontally or vertically. The orientation of the matrix is fixed.

(1) How many squares can be filled at maximum? How many codes can be made with such maximum filling?

(2) Consider the case in which five squares out of the fourteen are filled.
(A) Draw all the codes that can be made without filling the squares in the first and third columns from the left.
(B) How many codes can be made without filling the squares in the third and fifth columns from the left?
(C) When five squares out of the fourteen are filled, how many codes can be made?

(3) Let us consider how many codes can be made as the number of columns used is increased (e.g., only the leftmost column, only the two leftmost columns, ...). The case of no filling is counted as one. For example, the number of patterns to fill the leftmost column is three (as shown in Fig. 2).
(A) When only the two leftmost columns are used, draw all the patterns other than the one with no filled square.
(B) Consider only the three leftmost columns. How many codes can be made?
(C) Consider all the seven columns. How many codes can be made?

KEY: (1) 7; 2; (2)(B) 8; 102; (3)(B) 17; 577

How George Lasry Solves Ciphers in an Instant

George Lasry, a computer scientist and an expert in cryptanalysis, provided me with his "interim results" for an unsolved ciphertext found in BnF fr.4715, f.85. He has solved many historical ciphers (see "Unsolved Historical Ciphers") besides many other achievements outside my scope (Google Scholar). His "interim results" this time are interesting for me in that he calls it a "machine reconstruction."
He developed many related tools for cryptanalysis of historical ciphers, as well as language models based on historical text for algorithms to work effectively (e.g., his paper on papal ciphers: Lasry et al. (2021)). In addition to these, transcription of the ciphertext is the indispensable first step of any computer processing. He developed a manual tool to mark and classify graphic symbols, of which a glimpse can be made in the provisional decipherment below. (Text data is here.)

  In this case, Arabic figures 01-57 are assigned to symbols more or less in the order of frequency. Symbols 100-122 are ones occurring only once. His algorithm works for homophonic substitution of single letters, so he excluded 100-122 from cryptanalysis because they may not correspond to single letters, but prepositions, suffices, or even names. Of course, some of 01-57 may be syllables rather than letters, but as long as a sufficiently large proportion of these symbols represent letters, his algorithm may give meaningful fracments of words here and there.
In the above decipherment, there seem to be fragments of some Italian words: "scriver", "parlando", "contra", "francese", "signor", "..nditione", "ma consient...." There must be many errors in this "machine reconstruction", but hopefully someone versed in Italian may correct the assignment starting from these correspondence.

Enciphered Passage about Princess Henriette's Words to 2nd Earl of Chesterfield (1659)

An enciphered passage in the memoirs of Philip Stanhope, 2nd Earl of Chesterfield (Wikipedia), was kindly brought to my attention by Richard Merriman (image).
The memoirs, titled "some short notes for my remembrance of things and actidents, as they yearly happened to mee", is preserved in Add MS 19253 in the British Library (catalog, another catalog) and its main parts are printed in Letters of Philip, Second Earl of Chesterfield (1829) (Google).
The enciphered passage belongs to the year 1659. According to Letters (p.20, 105-106) (different from the narrative in Wikipedia), he killed a certain Wollies in a duel in January 1659 and fled to the Continent. In February, he wrote to Charles II in Brussels to obtain a royal pardon. For some time during this travel, he stayed in Paris, where he waited on Queen Mother and her daughter Princess Henriette, Charles II's youngest sister (who was to wed the Duke of Orleans in 1661). In 1659, Lord Chesterfield was 25, and Henriette was 15. The short ciphertext is something the latter did or said when he took leave. The following is my provisional transcription:
AYE25YALY9v4v5H21Y3Y545YAvLE&2TA2E85Y928T5.
16vTEvL+cc+8S1+2T9++8Y&93t9gFv1cATv93+EY93Y&Fv5Ev62T2vT.
Even before I completed the transcription, the cipher was solved by George Lasry. By filling a few blanks left by him, the paragraph can now be read (the deciphered text is in italics):

... but missing mee I went in to France and from thence in to Holland and waited on the King at Breda where I had his Majesties pardon, from thence, I went back againe through Flanders in to France where I stayd some time at Paris and waited on Queen Mother and her Daughter the Dutches of Orleans who when I took my leave desired me to forgive her fredoms & indiscretion upon so small acquaintance & that [I] would not have the wors[e] opinion[.] from Paris I went to Bourbon and after the having taken the waters there, I went to Callis and meeting the King as hee was comming from Holland on the sea I went in to his Majesties ship and waited on him in to England.


(March 2024) There was another correspondent with whom Henriette used a cipher. A letter of Henriette to Lord Fitzharding (in French), dated 19 December 1664, asks if he understands the cypher which she sent. (Google), p.279