Recently Solved Ciphers

I added some achievements (by me as well as by others) in 2018 in "Unsolved Historical Ciphers".

Undeciphered letters from Duke of Guise? (ca.1581)

Here are undeciphered letters to Mr de Mercoeur probably from the Duke of Guise.
I have been planning to write a background article but it will still take time. In the meantime, see
"Catalogue of Ciphers (Mainly Related to Duke of Nevers) in BnF fr.3995" for some contemporary French ciphers.
If someone achieves deciphering these, please let me know.

Undeciphered Letter to Emperor Charles V (1529)

An undeciphered letter to Emperor Charles V (24 May 1529) from Suarez de Figueroa, ambassador in Genoa is found in PARES. If someone succeeded in deciphering this, please let me know. (The strikeout on the ciphertext indicates it was deciphered at the time. A deciphered text may be found somewhare in the archives.)

I think the cipher (called the Figueroa-Charles V Cipher (1529) herein for convenience) was modelled after the Doria-Charles V Cipher (1528) (see here). If the subscript numerals consistently correspond to vowels, deciphering may not be so difficult, especially given that some word divisions are discernible.

Andrea Doria's Cipher (1528)

I updated the article "Ciphers during the Reign of Emperor Charles V" by adding a section of a cipher used by Genoese Admiral Andrea Doria in writing to Emperor Charles V.
This is the oldest vowel indicator system that I know. (Hence, I also updated "Tracing the Origin of Vowel Indicators in Spanish Ciphers" by mentioning the Doria-Charles V Cipher (1528).)

Catherine of Aragon's undecipherd letter

I found Catherine of Aragon's letter in cipher (3 November 1509) to her father, King Ferdinand of Spain, in the Spanish archives online. Unable to decipher it myself, I submitted it as a challenge at MTC3. To my pleasant surprise, two people have already solve it (which will be reflected on the MTC3 page soon). (Since the challenge is still open, I refrain from disclosing the solution.)

Since Catherine of Aragon was among the first who used cipher in the English court ("Earliest English Diplomatic Ciphers"), I have been looking for her ciphers. It is known that the Spanish archives have her letters in cipher.

For example, Catherine's first letter in cipher appears to have been that of 7 September 1507 (Bergenroth p.426), preserved in S.E.T.c.I. [i.e., Archivo General en Simancas, Estado, Tratados con Inglaterra] L.5.f.57. but I could not locate it online. Catherine's letters of the same date are found at
http://pares.mcu.es/ParesBusquedas20/catalogo/description/2208086
http://pares.mcu.es/ParesBusquedas20/catalogo/description/2208087
but these seem to be different.

As another example,
Bergenroth Suppl. p.33 has a letter originally deciphered by Almazan (20 March 1509), preserved in Archivo General de Simancas Patronato Real Tratados con Inglaterra, Legajo No.5 fo.60.


As yet another example, Catherine's letter of 29 July 1509, preserved in Britain, has a short passage in cipher (Brewer).

If any further cipher material related to Catherine of Aragon is available, please let me know.

Philip II's First Cipher (1543)

I uploaded "Philip II's First Cipher (1543)", which shows a reconstruction of Prince Philip's cipher when he was only sixteen. (Probably, the cipher was handled by a secretary.)
I also added a subsection for this cipher in "Ciphers during the Reign of Emperor Charles V".

Unsolved ciphers in the French archives (ca.1586-1593)

BnF fr.4715 in the French archives contains many materials in cipher (ca.1586-1593), including undeciphered ones.
I posted them in Undeciphered Letters in BnF fr.4715 in July.
Although I had solved some, no.59, no.61, and no.62 remain undeciphered. Also, no.38 seems to be in an interesting polyphonic cipher but I'm not sure yet.
If someone solves any of these, please let me know.

Two ciphers used in the first year of the reign of Philip II of Spain

I updated “Spanish Ciphers during the Reign of Philip II”. Specifically, I found examples of use of two ciphers before Cg.1. Both (“Suarez de Figueroa Cipher (1556)” and “Imperial Cipher of 1555”) turned out to be ones printed in Meister.
The earliest example I found of the Imperial Cipher of 1555 is from November 1555, after accession of Philip II. Since this is before Philip II expressed his resolution on 24 May 1556 to change the cipher of his father’s reign, I still think the Imperial Cipher of 1555 was inherited from Charles V’s reign. But there remains a possibility that this was created upon the new reign.
As for the Suarez de Figueroa Cipher (1556), both my reconstruction and the version printed in Meister are incomplete. Since there are undeciphered paragraphs in this cipher, further symbols may be identified by those versed in Spanish. (The struckout over the ciphertext shows it was deciphered by the recipient (or her clerk). A deciphered copy may be found somewhere in the archives.)

Spanish Ciphers: 1470-1479

In mid November, I uploaded “Spanish Ciphers before Accession of King Ferdinand: 1470-1479” at Academia.edu.
While the nineteenth-century historian Bergenroth once said Spanish ciphers were “simple and primitive” for about fifteen years after 1480, Spanish ciphers before 1480 are found in archives. I reconstructed Spanish ciphers used by Ferdinand the Catholic in letters to his father, King John II of Aragon in the 1470s. Two of them turned out to be rather complex.

New specimens of ciphered letters of Charles V’s time

I updated “Ciphers during the Reign of Emperor Charles V”.
Additional specimens I found in the Spanish archives necessitated the change in my appellations:
(old) the Imperial Cipher of 1547-1553
(new) the Imperial Cipher of 1544-1554
(old) the Imperial Cipher of 1548
(new) the Doria-Figueroa-Philip Cipher (1548)
As for the latter, the new specimens of this period seem to show this was not used widely. So I demoted the name.
When there are so many different ciphers, it is difficult to think of names to unambiguously specify particular ciphers. Ideally, I would like a name such as Leyva’s Cipher of 1536 if the creator’s name and date of creation were known. Alternatively, a name like Charles V-Prince Philip Cipher (1543-1544) is fine if the users and period of use were known and if information is not sufficient, the name is inevitably a provisional one. If a reasonably exhaustive catalogue can be made, simply the catalogue number may suffice.

Experimenting with a new blog platform

I plan to start a blog to report updates on my website: Cryptiana: Articles on Historical Cryptography and to solicit information for further updates.
I'm still experimenting with this platform.
First, I tried WordPress but its basic plan does not allow readers' subscription.
I'm going to move the few posts at WordPress here.