In cryptography it's a number, or letter, thrown in for the sake of appearance, or to confuse.
In this work the different methods of cryptography are classified.
Cryptography, krip-tog′ra-fi, n. the art of secret writing: the character or cipher so used.
He is the author of a work on cryptography, I believe, though I am ashamed to say I haven't yet read it.
I am not altogether ...