The Voynich Ninja

How simple is it to engineer and then have reverse engineered a modern superficial voynich imitation? Let's see. 

The imitation should probably use methods which 1) are plausible for the period, and 2) compatible with the ms.

To start, I have enciphered some English text in a way that the ciphertext could appear superficially similar to voynichese. The process used is deterministic, reversible, and with unoptimized parameters. Lots of mistakes must have been made.

What does it say in English?

FaiT Kzz nmnuy maig qar Tiooiea bar nmaei Tmz qooiea Tiaeean bar nmaei Teib Tiiiiz Tieir Kimb mvg Kaiin Fvg Tiiig Kieiiea kiin Fmq Fiiiiz mayun Taiyun qiiiaT mmq TIeig faaig Fiaean Kaaeaei Faiyun Foonuy Tiavinn Tiaeaei Tiiiig FaiT Kzz KaEg qiimiea mool mail maiiea Tiiiig Kiiag Kieiiea fieeean Tiig Kaiiea naaiben ner naek qeK niinuy mmiea TIayun nat Fooix famean fvT Kiiiyun Kaaaouy miig mmn tauYnh Fioog KaeiT kiaq meaei Tiavinn Tienuy Faiyun Foog fiin FvT Tiaaouy qayun Tiaean Kamean Fiin Faaei mael Fir Tian Fooyun Fiiiyun Faiyun FooT fiiir Tian Fooyun Fiiiyun Tiooz fieik faoob Kaeyun mmr teaei Tiaeean Fml mmq Fiaq meaei Tiavinn Tiiin Fooiea Tiaeean bar nmaei Teib miiiz fiiig Kaiin Faq Fmyun Kier mvr faaiaei Fmyun Taeaei Kamg Tieeg Faiyun nat Fooinuy mail Tiiiig qeK niinuy naeyun naz miiit Fooiouy Kianuy Kaiin Feig maaean TiiuYnh faoyun nanuy qiieiyun Fzl Fiag fiinuy faaiz Kaayun faob mmn Taig Kaayun Tieaei Keiyun nmyun naaean Fiig fiaean mvq qiimn maiK Fil meq qiiipen Kieaei Kiin Feez Kimz Kaal faainuy Fmean Fiit Fooiq Teiyun KaiT Kaiiean Tmpen Tial Taiz faaz fimg mail faaiiea Tiiiig Kieig TiiiT fiiinuy Tiiiiz Tieeg Kiar nmaei Kal kaeean Fmr nzg Kaeiz Kayun naean Fmg TaaT fiiinuy Timyun Taeaei nmnuy Tiaet fiaeben mail TIeig Tiiiig Fiiiz miinuy Fiiyun TaiK Kaab Fiviea qiial mooiyun nayun Kimaei KazT TiiiT fiiinuy Timyun Taeaei Tiaenuy TImr Feinuy kaaq qooil Fmean qiiiayun mzg Kaeiz Ka

Oh, you've changed the text so much with your last editing.

It's a dynamic cipher.

Ironically enough, it is this type of mid-stream editing (l did not see the first version) that may well explain the Currier “languages” and the possible transitional forms in between.  It is also a possible reason why the text can’t be solved as any kind of decryption/translation (trying to be non-provocative here) requires some level of consistency.  

So imagine the text of the first post, followed by the text of the “corrected” version (but a different plain text, of course) and try to solve what was said for the entire plain text.  The process of “correction” may bring the later versions to what was the original “intent” of the author but the shifting basis undermines the ability to get sense from the whole thing.

Unfortunately, it is easy to imagine an author at the time of the carbon dating, to be ignorant of the ultimate non-communicative effect of a constantly shifting “encoding” pattern.

If one were to stick within the same section or even bifolio though, the effect of code shifts can be assumed to be minimal. The biggest issue with this is that we have more difficulties comparing different sections, which would normally be an important strategy.

(15-07-2021, 10:54 AM)Searcher Wrote: You are not allowed to view links. Register or Login to view.Oh, you've changed the text so much with your last editing.

Yes, my apologies. There are two versions (maybe 2.5?? don't remember). The first had errors everywhere in the plaintext cuz of a logic error I missed in the program. Current version is correct.

(15-07-2021, 07:45 AM)byatan Wrote: You are not allowed to view links. Register or Login to view.How simple is it to engineer and then have reverse engineered a modern superficial voynich imitation? Let's see. 

The imitation should probably use methods which 1) are plausible for the period, and 2) compatible with the ms.

I once tried to generate a text from a given corpus (Regimen sanitatis Magnini Mediolanensis vol. 1), which has properties of the VMS. The success was moderate, but the basic idea to try an encryption with a calculation method well known in the Middle Ages ("russian peasant multiplication", also called "ethiopian multiplication") was acceptable in my opinion.

The result can be seen You are not allowed to view links. Register or Login to view.. The corresponding thread is You are not allowed to view links. Register or Login to view..

How many have actually attempted to solve this? It should be reasonably easy to solve, but I might have overestimated how easy since there's no solution yet. 

What proportion of members have solved crypto puzzles like this before?

Well, don't post the solution just yet. I'll take a look.

Assuming it's a verbose substitution cipher with some ambiguities (solved by the order of substitution), the first step would be to identify tokens. Some very low entropy combinations are obvious: "yu" is always followed by "n ", "y" always precedes "un", so "yun " (31 instances) is probably a token. Same for "nuy " (17 instances).

Trying to build a key that looks plausible without thinking too much about the alternatives, I quicky get more than 26 combinations (around 50 and probably missed a few) so maybe I tokenized too many combinations, or there are homophones, 2 per clear text letter maybe, or nulls.

Anyway, it seems difficult to crack without a good algorithm and a computer...