The Naibbe cipher

[magnesium]

I tried naibbe.py and decrypt_naibbe.py on a Latin text (1000 short lines) with default settings: no problem.

Despite this setting in naibbe.py:
UNAMBIGUOUS=True #True means bigram token generation avoids accidentally creating unigram word types. Strongly recommend True

I had an ambiguity at decryption every few lines, for example: ep(ma|it)aphium

2.7 Minimizing ambiguities during encryption and decryption
We can also preemptively eliminate ambiguity at the encryption stage. If we happen to encrypt a plaintext bigram as a word type reserved for unigram use, we can simply re-encrypt the bigram (by redrawing cards) so that it no longer matches a unigram word type.

Total ambiguity retries due to prefix+suffix collisions with unigrams: 798

No issue, but I'm just wondering: if these retries do not eliminate ambiguities completely, should there be more retries?

After 4 attempts I got a non-ambiguous ciphertext for "epitaphium", so it is possible: chedy dchdy qokaiin yte shy qokedy sheedy qokar.

In principle yes, there should be a loop that checks bigram-bigram ambiguity. I haven’t gotten there yet; I am working on it. As an interim solution I included the ambiguous decryption formatting under the UNAMBIGUOUS condition so that bigram-bigram ambiguity is at least visible.