27/07/2021

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".

24/07/2021

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.



19/07/2021

"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.

18/07/2021

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.