Engineering your own voynich

[byatan]

Of course, this does not imply that the cipher is reversible. For instance:

A -> Ti
B -> T
C -> i
D -> ii

Both AC and BD are ciphered as Tii. The cipher is deterministic but not reversible.

This is a good observation in the event that 'Tii' is your only ciphertext and you make certain assumptions about the format. In any case, don't worry, mine is reversible.