Mark Knowles' theories of pharma and other labels

[-JKP-]

... The key features of ciphers of that time was the use of nulls, homophones and a glossary...

I don't really agree with this, Mark.

The key feature of the diplomatic ciphers collected by Tranchedino is the one characteristic that you didn't mention—that they are one-to-many and many-to-one. This is how most of the text was constructed. The other characteristics were in there to slow down decryption, but I wouldn't call them key features. I would call them secondary features.

Yes, there were a handfuls of nulls available for use with each cipher, but they do not constitute the majority of the text and the nulls in these specific ciphers sometimes resembled each other, which would make them easier for a cryptanalyst to pick out as nulls.

Yes, there was a glossary for each cipher, but they were not extensive, and they were used as much for saving space (similar to medieval abbreviations) as they were for encipherment. They were mainly common names and words.

For example, there might be one or two characters to stand for the word "pope" or the name of the pope, but this character was generally different from the others, which means, to a cryptographer, it would stand out as different from common words constructed with individual letters. It would slow down decryption, but not stop it. A cryptanalyst intercepting a diplomatic cipher can see fairly quickly that it's one-to-many/many-to-one because of the overall patterns and would know beforehand that it is likely to contain names of important people and places and that these might be compressed (abbreviated) or glossary-enciphered.

Now in general nulls correspond to nonsense/meaningless text. Likewise homophones correspond to the scope for identical words being spelled in completely different ways.

The monotone quality of the VMS is quite different from ciphers that use homophones. In most cases, the VMS text shouts "less" rather than "more". Variety is lacking so it's less likely that homophones are a significant property of the text.

A glossary could apply in the context of rare symbols corresponding to specific words. I described before elsewhere how a diplomatic cipher key could be modified in a minor way to use glyph strings as an example of this.

Rare symbols in the VMS are very rare. If they were somewhat rare, appearing once every few pages, for example, then maybe they might constitute glossary words. As it is, however, they tend to be used so little, one can essentially ignore them until the other 200 pages are deciphered. It's a lot of text. If. you have only half a page of text, it's difficult to tell what is rare, and it's more important to try to work out what uncommon characters mean because they are proportionally greater, but the VMS is 200 pages, so rare characters can be dealt with after the rest of the text is deciphered.