# nonce

## Functions

| Function | Description |
| ------ | ------ |
| [deriveChunkNonce](/reference/filoz/filecoin-encryption-envelope/namespaces/nonce/functions/derivechunknonce/) | Derive the 12-byte AEAD nonce for one chunk: `baseNonce (7) ‖ chunkIndex (4, big-endian) ‖ last_flag (1)`. |