Phrase guide

Nihilist cipher

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

noun

Meaning 1

A symmetric cipher in which a Polybius square using a mixed alphabet is used to convert both the plain text and a keyword to a series of two-digit numbers, which are then summed in the normal way to get the ciphertext, with the key numbers repeated as required; (by extension) any of several improved algorithms based on this.

Definition source: English Wiktionary via Wiktextract

Usage: historical

Topics: computing, cryptography, engineering, mathematics, natural-sciences, physical-sciences, sciences

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Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

The cipher was originally used by Russian Nihilists in the 1880s to organise terrorism against the tsarist regime.