ConceptsKeyed alphabet
Concept · cryptography · in 2 mysteries
Keyed alphabet
A cipher alphabet that starts with a key word and continues with the letters not yet used.
An alphabet written out with a key word first (repeated letters dropped) and the remaining letters following in order. Kryptos uses one keyed by KRYPTOS on the sculpture's right-hand panel, and the readings of K4 that work start from it. A keyed alphabet turns a guessable shift into one that needs the word.
Where it comes up
Voynich Manuscript
The substitution changes with position in the line (a line-keyed or position-keyed alphabet), so that the same plaintext at the same offset in different lines appears as glyph-disjoint isomorphs.
Kryptos
K4 uses a Gromark-type cipher (a keyed alphabet with a running numeric key generated by chain addition) or a close relative.
Cite it
Mysteries Department. (2026). Keyed alphabet [Concept CPT0DECW00PYYD3]. https://mysteriesdept.com/r/CPT0DECW00PYYD3
@misc{mysteriesdept_cpt0decw00pyyd3,
title = {Keyed alphabet},
author = {{Mysteries Department}},
year = {2026},
note = {Concept, catalog key CPT0DECW00PYYD3},
url = {https://mysteriesdept.com/r/CPT0DECW00PYYD3}
}