Did Beaufort Really Use the Beaufort Cipher?

I uploaded a new article: "Did Beaufort Really Use the Beaufort Cipher?".
The Beaufort cipher is a variant of the Vigenere cipher, so called because it was invented by Admiral Francis Beaufort. But it appears that Beaufort himself never used the cipher himself. The cipher Beaufort used in letters to his brother or his secret diary was more primitive.
The article also discusses when the Beaufort cipher was published. (I was induced to check this when I read Lewis Carroll may have known of the Beaufort cipher.) Some say it was published in 1857, but considering that Beaufort died on 17 December 1857, this dating does not seem to refer to an actual date of publication. Maybe, some writers simply quoted the year of the admiral's death. At least, it was only after the (re?)publication in 1870 that the Beaufort cipher became widely known. (The version published in 1855 on a magazine was actually the conventional Vigenere cipher, as pointed out by Franksen.) 

 

Two-Part Code vs. One-Part Code: Degrees of Irregularity

I mentioned Karl de Leeuw's book the other day. I (re)read it because I remembered it described code in which figures runs vertically, while words are arranged horizontally. Such a two-dimensional arrangement introduces some irregularity without the need to have separate tables for encoding and decoding. I occasionally used the term "two-part code" to describe such a system, but I realized that when the code is "dense" (including many words with the same initial letter in one row), it does not seem appropriate to call it "two-part." I added a new sectioin on this terminology in "Code, Cipher, Nomenclator -- Notes on Terms in Cryptology".
I checked my usage of the term "two part" for this kind of arrangement. In most of the cases, I used the term with a reservation that the arrangement is not completely random. But I'm going to add a note about this in one of my previous posts: "Cardinal Mazarin Used Two-Part Code ".

Dutch Crypto-History

I uploaded a new article about Dutch crypto-history in Japanese ("オランダ暗号小史").
I started it as excerpts from Karl de Leeuw's book for my personal memorandum, but it grew into a bit more than that. I included some undeciphered ciphertexts I found in Thurloe State Papers more than ten years ago. For a long time, I thought the plaintext was in Dutch, but I now think French is more probable.

Athanasius Kircher and Codebreaking

I read that Athanasius Kircher occasionally deciphered intercepted Swedish letters (presumably during the Thirty Years' War). I mentioned this in "Habsburg Codes and Ciphers" as a stub for future expansion.

A Danish Diplomatic Cipher with Table Swtiching in the 17th Century

I uploaded another small article "A Danish Diplomatic Cipher with Table Swtiching in the 17th Century" using the same source as yesterday. One interesting feature of this cipher is that it has five different substitution alphabets, which are switched by indicators. This appears to belong to the 1680s or thereabout, not to the time of Christian IV.

A Letter Code of Emigres in Koblenz

I uploaded a small article "A Letter Code of Emigres in Koblenz." It presents a cipher used by exiled royal princes in the years immediately after the French Revolution in 1789.

Which Cipher of Henrietta-Maria Did Babbage Solve?

Mathematician Charles Babbage's papers show he solved a cipher of Henrietta-Maria, queen of King Charles I of England. Now, I identified it is what I call "Third Cipher between Charles I and Henrietta-Maria" in King Charles I's Ciphers.
I reflected it in "Charles I's Cipher Revealed: Sir Charles Wheatstone's Codebreaking", the first update since its release in 2009 (which was even before I posted "King Charles I's Ciphers", by the way).