Nihilist cipher

noun

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.

Ask AI about this wordChatGPTClaudePerplexityGoogle AIGrok

Meanings

nounNihilist cipher (plural Nihilist ciphers)

plural Nihilist ciphers

  1. historicalcomputerA 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.

Origin

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

Full word history & related roots →
Cite this entry
APA

Nihilist cipher. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Nihilist%20cipher

MLA

“Nihilist cipher.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Nihilist%20cipher. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Nihilist cipher,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Nihilist%20cipher.

Source: Nihilist cipher on Wiktionary, CC BY-SA 4.0.