Abscissa-derived linear keys

Fixed-step keys and fixed-step letter reorderings suggested by ABSCISSA, the K2 keyword (it means the x-coordinate)

In plain English: Fixed-step keys and fixed-step letter reorderings suggested by ABSCISSA, the K2 keyword (it means the x-coordinate), using a key that increases by a fixed amount at each position. Every combination within the stated scope was tested (238 thousand configurations); none produced a valid solution. This record is negative within the tested scope.

NOISE Tier 2

How to read this record

Verdict – ELIMINATED (ruled out within the tested scope), NOISE (nothing beyond what chance produces for a search of this size; also shown when a record stored no verdict of its own), INCONCLUSIVE (the test left candidates or options standing, or could not decide, so it does not rule the method out), 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, valid while its stated assumptions hold. Tier 2 = every possibility within the stated scope tested. Tier 3 = partially tested or sampled. Tier 4 = not yet properly 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). N/A means no such score could be read from this record.
Keystream Consistency (Bean) – Whether the key values at different positions are mathematically consistent with each other. The check only holds when the known letters stay in their carved positions (no letters rearranged or removed), and the full set used here assumes the standard A to Z alphabet.
Scope Limitations – What this elimination does not rule out.

Configs Tested: 237,672
Best Score: 7 / 24 known letters matched · low, no sign of a solution
Confidence: Tier 2: Exhaustive search under stated assumptions. Does not eliminate multi-layer variants.
Date Tested: 2026-02-17
Script: scripts/exploration/e_bespoke_02_abscissa_linear.py

Scope Limitations

This elimination does not rule out:

Tests every key that changes by a fixed step from one letter to the next (all 26 step sizes and 26 starting values, Vigenere, Beaufort and Variant Beaufort) applied directly to the carved text, and letter reorderings of the same fixed-step form using selected sculpture-derived settings, alone or followed by such a key or by one of six keyword keys. Also tries affine letter substitution and some cut-off and coordinate-pair readings. Other reorderings, other key forms and other multi-layer uses of the idea are not ruled out.

Assumptions

Key values or reordering steps follow a fixed-step (linear) formula
Standard A-Z alphabet

Reproduce

PYTHONPATH=src python3 -u scripts/exploration/e_bespoke_02_abscissa_linear.py

Requires the kryptos repo, Python 3.11+, PYTHONPATH=src. Some recent scripts may not be in the public repository yet.

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