substitution cipher

noun

, Cryptography.

1. a cipher that replaces letters of the plain text with another set of letters or symbols.

Word History and Origins

Origin of substitution cipher¹

First recorded in 1935–40

Example Sentences

Then why didn't the Germans use a substitution cipher when they sent this message about the transports?

From Project Gutenberg

That brought the message down to the simple and straightforward matter of a substitution cipher.

From Project Gutenberg