Hill cipher with YAR-derived matrix parameters (width 9)

Hill cipher with YAR-derived matrix parameters (width 9, 2x2 and 3x3)

In plain English: Hill cipher with YAR-derived matrix parameters (width 9, 2x2 and 3x3) — using a method that encrypts groups of letters using matrix multiplication (Hill cipher). Mathematically proven impossible — no key or setting can make it work. This approach is ruled out within the tested scope.

ELIMINATED Tier 1

How to read this record

Verdict – NOISE (no better than random guessing), INTERESTING (slightly above random, almost certainly coincidence), SIGNAL (statistically unusual, warrants investigation), or FULL MATCH (all 24 known letters correct).
Confidence Tier – Tier 1 = mathematical proof (permanent). Tier 2 = every possibility tested. Tier 3 = partially tested. Tier 4 = not yet tested.
Configs Tested – How many different key/parameter combinations were tried.
Best Score – How many of the 24 known plaintext letters the best attempt matched (out of 24).
Keystream Consistency (Bean) – Whether the key values at different positions are mathematically consistent with each other.
Scope Limitations – What this elimination does not rule out.

Configs Tested: 2,000
Best Score: 0 / 24 known letters matched · no better than random guessing (random guess would score: 0.0)
Keystream Consistency (Bean): FAIL
Checks whether the key values at different positions are mathematically consistent with each other.
Confidence: Tier 1: Mathematical proof. Permanently valid unless cribs or CT are wrong.
Date Tested: 2026-02-18
Script: scripts/substitution/e_s_151_hill_w9_yart.py

Scope Limitations

This elimination does not rule out:

Tested Hill 2x2 and 3x3 with YAR/RQ parameters. Hill cipher is structurally incompatible with K4 crib pattern.

Assumptions

YAR superscript values (Y=24, A=0, R=17) form Hill cipher matrix

Reproduce

PYTHONPATH=src python3 -u scripts/substitution/e_s_151_hill_w9_yart.py

Requires the kryptos repo, Python 3.11+, PYTHONPATH=src.

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