Solution of William Perwich's Transposition Cipher (1/2)

Regarding the unsolved transposition cipher of William Perwich posted at the TNA blog on 4 August and my blog on 19 September, Norbert Biermann made a breakthrough on 27 September (GMT). While the ciphertext rows have variable length, he suggested that "each line represents a single column of the grid" with a variable number of nulls added at the end. He observed that such use of nulls is consistent with the instructions to Southwell and to Gascoigne.
If the grid thus obtained by removing nulls beyond the 21st position on each row is correct, the remaining problem is likely to be an ordinary columnar transposition cipher.
When George Lasry applied his solver next day, he immediately came up with a promising preliminary result. While there were still some odd columns (in the deciphered text), Norbert proposed removing the first column and rearranging the remaining odd columns. George found supplying two missing letters in the ciphertext further improves the deciphered text. At this time, about 90-95% was solved. (Occasional transcription errors had to be corrected.) I also joined the discussion and we further discussed code numbers. Now we are fine tuning the final text. (The deciphered text reads: "the souldiers grumble much....")
While we were fine tuning, an email came in reporting an independent solution.

A Wish to End Hunger from Wartime Experience in a Crypto Unit of the Author of Anpanman

Anpanman is the hero of a popular Japanese picture book series for kids. Its creator, Takashi Yanase (1919-2013), served in a crypto unit in the Japanese Army during WWII. I uploaded a short article in Japanese about his wartime career.
I found this by googling because I recently learned in a TV serial inspired by the lives of Yanase and his wife that what seems to be a childish episode (like giving out anpan, a sweet bun filled with red bean paste) is actually rooted in his deep desire to end hunger in the world.
Yanase's crypto unit did not go through intense combat during the war but suffered greatly by starvation. Yanase once said he wanted to convey the message that "you can end hunger by sharing and you can live together even with people you don't like".
The reversal of values following Japan's defeat in 1945 had a profound impact on Yanase. He said, "The one value that never gets reversed is devotion and love.... If someone is dying of hunger before your eyes, you give them a piece of bread. That is the starting point of Anpanman."

(Photo taken by my son in 2023.)

Correspondence between Emperor Ferdinand III and Governor of the Spanish Netherlands (1634, 1635, 1640)

I updated "Unsolved Historical Ciphers" with information I mentioned in the last few posts and further added entries about Emperor Ferdinand III.

An Undeciphered Transposition Cipher of William Perwich, an English Agent in Paris (1670)

An undeciphered ciphertext in a letter from William Perwich to Lord Arlington, Paris, 9 April 1670 NS (TNA SP78/129, f.180) is presented in a blog post of The National Archives (TNA). (I thank Norbert Biermann for drawing my attention to this last month.) It appears to be a transposition cipher, given the letter frequencies as well as the occurrence of abbreviations such as ye(=the) or yt(=that).

My transcription of the ciphertext is here, which is slightly different from the version given on the TNA blog. I grouped some letters (e.g., "QR" on the first line and the second last line) but I'm not so sure of this. Actually, without such grouping, there are exactly 500 elements (excluding the last "likelyhood"), which is plausible in a transposition cipher, suggesting a transposition matrix of 25x20, 20x25, 10x50, etc.
Assuming columnar transposition (a Dutch example from 1675), I (manually) tried various matrix sizes (not limited to the factors of 500) and looked for matrix dimensions that might allow transposition of columns (or rows) to align Qs and Us, but it was not successful. (I assumed transcription of Q and U was correct.)

The TNA blog points out a possibility that this employs Samnuel Morland's scheme (see my article quoted therein) used by some English diplomats at the time. Indeed, Sir William Temple wrote in 1669 "Mr. Perwick wrote from France for a Tryal between us" about "Sir Samuel Mroland's Cypher".
Actually, the transposition scheme proposed by Samuel Morland is not limited to rectangular matrices, but can employ a triangle, a pentagon, a hexagon, or even more irregular patterns. But considering that "ruled papers" were supplied, I think use of non-rectangular matrices is not likely.
We may consider various patterns for inserting nulls by studying known examples.

The letter is calendared on p.82 of M. Beryl Curran (ed.) (1903), The Despatches of William Perwich, English Agent in Paris, 1669-1677 (Wikimedia Commons), which silently omits the paragraph in cipher. (The first paragraph of the letter belongs to another letter in the calendar from the same date addressed to Sir Joseph Williamson, with some difference in wording. Probably, the calendar omits such repetition to different recipients.)

Variable-length Numerical Code in Austrian Archives

Given a ciphertext in digits continuously written without a break, its deciphering requires breaking the stream of digits into individual code groups. Although various schemes to allow it have been known for Italian ciphers, I noticed more elaborate schemes are documented in the Austrian archives, which are described in my new article, "Variable-Length Numerical Code in Austrian Archives". Some undeciphered ciphertexts (probably of a more basic type) are also presented.

A French TV Documentary on the Codebreaking of Mary Stuart's Letters Premiered in Paris

The 2023 discovery of more than fifty ciphered letters by Mary Stuart (which I reported here) received worldwide media coverage. The story of Mary Stuart, with a particular focus on our codebreaking, has now been made into a French TV documentary, Marie Stuart, l'énigme des lettres codées. The program not only portrays the tragic queen's later life through high-quality reenactments and interviews with historians, but also highlights how her coded letters were deciphered, featuring interviews with the three of us, the authors of the original paper. (Yes, I appear in it!)

The program is scheduled to air on ARTE in France on 27 September (program guide). Ahead of the broadcast, the world premiere took place on 16 September at the BnF -- the French National Library where Mary's coded letters had been preserved for centuries without being recognized as such).

The trailer is available on YouTube.

Cipher of Imperial Ambassador Juan Perez (1527)

The cipher used in a letter from Juan Perez to Emperor Charles V turned out to be the same as the one used by his predecessor, Juan Manuel, of which I uploaded my reconstruction yesterday. Although I listed the letter in "Unsolved Historical Ciphers", it seems to be calendared in CSP Spain. (I will update relevant articles when my PC comes back from repair.) 

 

Correspondence of Imperial Ambassador Juan Manuel (1522)

I updated the article uploaded the other day to cover a cipher between Juan Manuel and Charles V under a new title "Correspondence in Cipher of Imperial Ambassadors Alonso Sanchez and Juan Manuel (1522)".
Although the 28 letters from Juan Manuel to the Emperor are labelled "Non-decrypted" in DECODE, I noticed the first page of decipherment is visible in all but two of these records. Decryption may be found in the archives for the remaining two (R9501 and R9515, of which at least the former is calendared in CSP).

Correspondence of Imperial Ambassador Alonzo Sanchez (1522)

I reconstructed a cipher used between Alonso Sanchez and Emperor Charles V and uploaded it in a new article "Correspondence in Cipher of Imperial Ambassador Alonso Sanchez (1522)". It is similar to known ciphers for other ambassadors at the time, in the tradition of the Spanish ciphers from the time of Ferdinand and Isabella.
This will allow reading many undeciphered letters, including the two in the DECODE database that I reported in May in "Unsolved Historical Ciphers". (For some of the letters marked "Non-decrypted" in DECODE, plaintext is avaiable. So it is advised to check before working.) For example, the beginning of one of the two I reported in May, R9509 (which is recorded more fully in R9596) can be read as:
- - - - - A [xix] de es-t-e escrevi a vuestra magestad a-z-i-en-do-l-e s-a-b-e-r lo que lo-s de esta r-e-publica me r-e-s-p-o-n-di-e-r-o-n a c-a-b-o z-e [s/t...?].

Can a Vigenere Cipher be Broken without Key Repetition?

I've been interested in whether a Vigenere cipher without key repetition can be solved. If the key is random, it is a one-time pad and is theoretically unbreakable. On the other hand, if the key is a natural language text, I heard such a cipher (called a running key cipher) can be solved. But how?
I uploaded a new article about this: "Solving Running Key Ciphers (Manually/Digitally)".

A Florentine Polyalphabetic Cipher from the 1480s

I learned in a paper by Marco Vito that the instruction for a Florentine cipher from the 1480s prescribes its use as a polyalphabetic cipher. This is the only actual example of a polyalphabetic cipher before 1560 known to me (not counting the treatises by Alberti and Trithemius as actual examples).
This induced me to collect specimens of polyalphabetic ciphers known to me as a new article, "Polyalphabetic Ciphers before 1600".

Japanese Cipher Disks during the Meiji Period

I uploaded a new article in Japanese about cipher disks used in Japan during the Meiij Period. At the time, Japan was just starting to use Western-style ciphers and the cipher disks were not used for a polyalphabetic cipher, but only for switching the monoalphabetic substitution table.
While some of these have already been mentioned in some of my articles, I sorted those with new materials I came across recently, including (1) telegrams in relation to the assassination attempt on the Tsarevich (1891) (Wikipedia) and (2) photos of actual cipher disks used in post offices.

Related website: "Cipher Wheel of The Meiji Era's Cryptographic Wheel" (Modern Japan in archives) (2006-2010)

Real Messages Encrypted by Japanese RED Machine

Two authentic messages encrypted by using RED (1937) are recorded in a document declassified by NSA (REF ID: A71152), which I recently learned from Jean-François Bouchaudy.
The messages are:
(1) Ambassador in Berlin ("Mushakoji" [Wikipedia]) to Foreign Minister in Tokyo (Arita [Wikipedia]), 4 January 1937 (ciphertext, raw decryption, English translation).
(2) From Tokyo to ambassador in Berlin, 8 January 1937 (ciphertext, raw decryption) with decryption in romaji and English translation (somehow dated "9 January 1937").

Bouchaudy learned of this document from George Lasry in June 2025, who quickly found the key to the two messages. Then, Bouchaudy succeeded in reproducing the decryption by the RED simulator he developed.
He reports the results on his website, in which I contributed in parsing the raw decryption of the first message into words in Japanese.

For people interested in ciphertext encrypted by RED, Bouchaudy "created" 9 problems in the form of historical correspondence among US codebreakers. He tells us they (not authentic RED messages) are based on the wiring of the examples given in Alan G. Konheim (2007), Computer Security and Cryptography (which deals with RED and PURPLE in Chapter 7).

Deavours and Kruth (1985), Machine Cryptography and Modern Cryptanalysis has a paragraph in RED (p.213), but Bouchaudy tells us it is different from RED because it "has no Period".

"Cipher Disk" before Alberti

I recently learned that before Leon Battista Alberti's treatise, there had been ideas similar to his cipher disk. In particular, Giovanni Fontana's disk for mnemonics looks very similar to Alberti's cipher disk, though there is no evidence Alberti knew this. (Another interesting thing about Fontana is that his ideas are described in a manuscript booklet almost entirely in cipher.)
I uploaded a short article about this: "Giovanni Fontana's "Cipher Disk" (ca. 1430) in an Encrypted Booklet". (This was delayed several weeks because of troubles of my PC....)

An Original French Naval Code (1778)

An original French code (1778) is reproduced in Pierrot, Chaline, Damoiseau-Malraux, Mekhail, Perret (2025), "A Caribbean Directory-based Encryption during the American War of Independence" (HistoCrypt 2025).
It was for D'Agoût, governor of Saint Domingue (1777-1780). It is a two-part code consisting of a table for encoding in alphabetical order and a separate table for decoding in numerical order. The substitution table assigns three figures for the vowels and one figure to the other letters and the ampersand.
The nomenclature includes entries for syllables and common words. As was typical with French ciphers, some variants are covered by one entry: "action, s" (for "action", "actions"), "it, e" (for "it", "ite"), "puis, que" (for "puis", "puisque").
It should be noted that the codes are made on printed templates. The template for encoding has syllables and words printed in alphabetical order, with a section "NOMS de Lieux" in which place names are not printed and are filled when preparing a code for a specific application. The decoding table has printed numbers 1-850.

Pierrot et al. (2025) reports their reconstruction of a similar code used in 1782 between Guillaume de Bellecombe, governor of Saint Domingue a few years after D'Agoût (1782-1883), and the Secretary of State for the Navy. The number ranges up to 857. There might have been a necessity for additional entries 851-857 beyond the template range 1-850.

Contemporary French diplomatic codes I know had 1200 entries (Barbé-Marbois (1782), Luzerne (1781), Napoleonic age), larger than these naval codes. On the other hand, the code used in one undecoded message between Admiral D'Estaing and Gerard, French minister in Philadelphia, (1779) ("Unsolved Historical Ciphers") has a highest number 597.

Tuple Ciphers (Enciphering a letter with two letters)

I read about reconstruction of an interesting cipher (1537-1547) in a paper by Lasry, Simonetta, and Biermann in HistoCrypt 2025. It enciphers a letter with two letters, while enciphering a syllable with a letter. Moreover, frequent omission of the dot to distinguish syllables makes it look polyphonic. My new short article "Tuple Cipher -- Enciphering a Letter with Multiple Letters" focuses on the aspect of enciphering a letter with multiple symbols.

Dutch Codebreaking Activities during WWI

Florentijn van Kampen (2025), 'Dutch Cryptanalysis of Four American Diplomatic Codes in World War I' (HistoCrypt 2025) is interesting in describing Dutch codebreaking activities during WWI. Beside that, it presents examples of how code (as opposed to a cipher) can be broken. It is also valuable for me to show sources about the US State Department Codes. I updated "How to Break a Code (Not a Cipher)" and "Red and Blue: First Official Codebooks Adapted for Telegraphy" by mentioning these.

Verification of Decryption of Beale Cipher No.2

I have not paid much attention to the famous cryptogram known as the Beal Ciphers (No.1 - No.3). Many consider them a hoax, but at least the Beale Cipher No.2 can be deciphered by using the Declaration of Independence as a key. I recently read that it has been pointed out that deciphering the Beale Cipher No.2 with the given key is not so straightforward. Indeed, there are numerous errors in the numbers. Although the correct reading might have been achieved by close study, it seems unnatural that such painstaking effort is not mentioned in the original pamphlet.
I uploaded a new article ("Errors in Beale Cipher No.2") about this.
(It's a pure coincidence that it's the Independence Day today.)

A Cipher of Eleanor of Navarre (1476)

I uploaded a short article "A Cipher between Eleanor of Navarre and her Father, John II of Aragon (1476)" presenting a simple cipher used between Eleanor of Navarre and her father, John II of Aragon (1476).

Imperial Ambassadors in the 1520s (Juan Manuel, Alonso Sanchez)

I added entries for Juan Manuel (imperial ambassador in Rome) and Alonso Sanchez (imperial ambassador in Venice) in "Unsolved Historical Ciphers". Searching archives may be more helpful than cryptographic methods for these ciphers with many nomenclature entries.