Run · Voynich Manuscript

T41 generation 3: difficulty ladder for lattice EM on the planted control (no homophones, homophones, copied nulls)

Each rung's control is Pliny NH 16 enciphered by period.generate seed 77 with that rung's setting.

No rung passes, not even a one-sign-per-letter key with no nulls. The limit is not homophones or nulls but the sign set itself: signs are overlapping glyph chunks (o, ok, oke...), so many segmentations read as Latin-like letter sequences under a bigram element model, and coverage stays at the permuted-key level whatever the key accuracy. At Herbal A's length (4,700 training words) this family's key cannot be recovered with learned boundaries by T40's solver or by lattice EM.L1 one sign per letter, no nulls, no line layer: key 0.376, coverage 0.312 (bar 0.483). L2 four homophones per consonant: key 0.556, coverage 0.334 (bar 0.487). L3 plus 30 % copied nulls: key 0.247, coverage 0.327 (bar 0.488). (L4 = full setting with line layer, generation 1: key 0.364, coverage 0.324.)0

Result

Run	Measured	Result	Against	Decision	Date
Run	Held-out key accuracy by use / dictionary coverage (bar 0.7 x true plaintext's) per rung	L1 one sign per letter, no nulls, no line layer: key 0.376, coverage 0.312 (bar 0.483). L2 four homophones per consonant: key 0.556, coverage 0.334 (bar 0.487). L3 plus 30 % copied nulls: key 0.247, coverage 0.327 (bar 0.488). (L4 = full setting with line layer, generation 1: key 0.364, coverage 0.324.)	Permuted-key coverage 0.25-0.29 per rung · M-T40 rung A (true boundaries): key 0.706	No rung passes, not even a one-sign-per-letter key with no nulls. The limit is not homophones or nulls but the sign set itself: signs are overlapping glyph chunks (o, ok, oke...), so many segmentations read as Latin-like letter sequences under a bigram element model, and coverage stays at the permuted-key level whatever the key accuracy. At Herbal A's length (4,700 training words) this family's key cannot be recovered with learned boundaries by T40's solver or by lattice EM.

What it used and found

Lattice EM decipherment: sign boundaries and key learned together, with a structure-preserving null

Method

MTH

Herbal A and Herbal B paragraph text: training and held-out pages

Dataset

DAT

Latin genre texts

Dataset

DAT

Naibbe cipher tables and example plaintexts (greshko/naibbe-cipher, commit 719f2f4c)

Dataset

DAT

Latin as a re-spaced homophonic stream (period practices)

Answer it tests

ANS

Parameters

L1 = {'h_c': 1, 'h_v': 1, 'p_copy': 0}, L2 = {'h_c': 4, 'h_v': 1, 'p_copy': 0}, L3 = {'h_c': 4, 'h_v': 1, 'p_copy': 0.3}, pw = 0.25, alpha = 0.05, common = {'K': 50, 'lam': 0, 'Ssyl': 0, 'abbrev': 0, 'p_stay': 0.9, 'window': 5, 'novowel': 0, 'p_break': 0.5, 'spacing': 'stream', 'simplify': 1, 'positional': 0}, restarts = 30, permutations = 10, em_iterations = 60

Cite it

Mysteries Department. (2026). T41 generation 3: difficulty ladder for lattice EM on the planted control (no homophones, homophones, copied nulls) [Run RUN0DCFZ7YRGFX7]. https://mysteriesdept.com/r/RUN0DCFZ7YRGFX7

@misc{mysteriesdept_run0dcfz7yrgfx7,
  title     = {T41 generation 3: difficulty ladder for lattice EM on the planted control (no homophones, homophones, copied nulls)},
  author    = {{Mysteries Department}},
  year      = {2026},
  note      = {Run, catalog key RUN0DCFZ7YRGFX7},
  url       = {https://mysteriesdept.com/r/RUN0DCFZ7YRGFX7}
}