05-07-2018, 04:56 AM
I can think of so many different ways that frame shifting can occur in ciphers that I thought it deserved its own thread.
On the simplest level, imagine a code ring with an alphabet on each wheel. If we spin the wheel so that A matches up with V (instead of A), then we have created a new frame of reference from which the code is derived. Thus, F is A, L is G, etc. It's a simple Caesar cipher.
We can use the same frame of reference for the entire block of text or we can shift the wheel every few characters (based on a regular number of characters or based on some pre-arranged pattern or marker).
![[Image: CodeWheelShiftReference.png]](https://voynichportal.com/wp-content/uploads/2018/07/CodeWheelShiftReference.png)
Now, if this were a genetic frame of reference, we would examine groupings according to known patterns. However, if a mutation occurs (an insertion or deletion), a sequencing error would affect the boundary expectations, and thus the accuracy of the subsequent patterns.
This can happen in a code ring also.
Imagine you invented a cipher in which you have organized the letters into groups (groups of words, or groups of a certain length, or groups with certain delimiters) and you shift your code ring (your frame of reference) each time you reach a group boundary. If you miss a boundary then a "mutation" occurs and the text that follows may be off.
If you are deciphering the text, you have to work out the frame of reference and how the groups are organized. Even if the enciphered text is accurate, it's possible that a "mutation" (a mistake) might occur in the decipherment process, then the rest would come out wrong. (This concept would also apply to reading relative-notation music systems. If you start off on the wrong note, the notes that follow will be in the wrong key.)
A "frame shift" can be a deliberate part of the encipherment process. Cipher wheels have been invented that can shift multiple times or at predetermined intervals. In the Middle Ages, they sometimes created charts full of shifts (usually regular shifts). In fact, we already have a forum thread to discuss a specific kind of shift.
In the 1460s, Alberti was using multiple substitution codes, and indicated the frame [of reference] shift in the text itself. So markers and shifts did exist in the 15th century.
If frame shifts were used in the encirpherment, they would also have to be part of the decipherment process.
The VMS does not show evidence of being a simple substitution code, nor does it show signs of being a regularly shifted substitution code (the same common tokens show up throughout the manuscript on almost every line). But it is possible there are markers—certain glyphs show up with great regularity in places where one might expect more variety, so it is possible there are larger blocks of text that might have to be interpreted with some kind of shift in mind. In fact, the first time I saw the VMS, I wondered if the P and Eva-k gallows at the beginnings of paragraphs were "keys" that meant, "This paragraph is to be decoded according to this pattern." (I soon realized it wasn't that simple and that they might be pilcrows or symbols, or letters, or something else entirely.)
Anyway, M. Hoffmann stated that one needs a degree in science to understand frame shifts. I don't agree. I think it's something that can be understood on a logical level, and even though the above is a very simple example, the concepts can be applied with varying levels of complexity.
On the simplest level, imagine a code ring with an alphabet on each wheel. If we spin the wheel so that A matches up with V (instead of A), then we have created a new frame of reference from which the code is derived. Thus, F is A, L is G, etc. It's a simple Caesar cipher.
We can use the same frame of reference for the entire block of text or we can shift the wheel every few characters (based on a regular number of characters or based on some pre-arranged pattern or marker).
Now, if this were a genetic frame of reference, we would examine groupings according to known patterns. However, if a mutation occurs (an insertion or deletion), a sequencing error would affect the boundary expectations, and thus the accuracy of the subsequent patterns.
This can happen in a code ring also.
Imagine you invented a cipher in which you have organized the letters into groups (groups of words, or groups of a certain length, or groups with certain delimiters) and you shift your code ring (your frame of reference) each time you reach a group boundary. If you miss a boundary then a "mutation" occurs and the text that follows may be off.
If you are deciphering the text, you have to work out the frame of reference and how the groups are organized. Even if the enciphered text is accurate, it's possible that a "mutation" (a mistake) might occur in the decipherment process, then the rest would come out wrong. (This concept would also apply to reading relative-notation music systems. If you start off on the wrong note, the notes that follow will be in the wrong key.)
A "frame shift" can be a deliberate part of the encipherment process. Cipher wheels have been invented that can shift multiple times or at predetermined intervals. In the Middle Ages, they sometimes created charts full of shifts (usually regular shifts). In fact, we already have a forum thread to discuss a specific kind of shift.
In the 1460s, Alberti was using multiple substitution codes, and indicated the frame [of reference] shift in the text itself. So markers and shifts did exist in the 15th century.
If frame shifts were used in the encirpherment, they would also have to be part of the decipherment process.
The VMS does not show evidence of being a simple substitution code, nor does it show signs of being a regularly shifted substitution code (the same common tokens show up throughout the manuscript on almost every line). But it is possible there are markers—certain glyphs show up with great regularity in places where one might expect more variety, so it is possible there are larger blocks of text that might have to be interpreted with some kind of shift in mind. In fact, the first time I saw the VMS, I wondered if the P and Eva-k gallows at the beginnings of paragraphs were "keys" that meant, "This paragraph is to be decoded according to this pattern." (I soon realized it wasn't that simple and that they might be pilcrows or symbols, or letters, or something else entirely.)
Anyway, M. Hoffmann stated that one needs a degree in science to understand frame shifts. I don't agree. I think it's something that can be understood on a logical level, and even though the above is a very simple example, the concepts can be applied with varying levels of complexity.
![[Image: CodIcon242CodeWheel.png]](https://voynichportal.com/wp-content/uploads/2018/07/CodIcon242CodeWheel.png)