nonce
termcryptographysecurity
Stands for: number used once
A number used once, included in a protocol so the same message cannot be replayed.
A nonce guarantees freshness: because it never repeats, a captured request cannot be resent to fool the receiver. It is distinct from an IV and from a salt, though all three inject uniqueness; the nonce's specific job is defeating replay.
Also known as: number used once, cryptographic nonce