Nonce Reuse

Nonce reuse occurs when a cryptographic operation repeats a nonce in a context that requires uniqueness, commonly under the same key. With encryption modes such as AES-GCM, this can compromise confidentiality and authentication rather than merely reduce randomness.

Safe generation must account for concurrent workers, restarts, and the total number of operations. The exact requirement belongs to the algorithm and protocol, so a nonce must not be assumed interchangeable with a reusable session identifier.