Module broadcast 

HAP-BLE broadcast-notification encryption key. The accessory broadcasts encrypted value changes in its advertisements while disconnected; the controller decrypts them with this key, derived once per broadcast-key generation and persisted as pairing material.

Broadcasts use a ChaCha20-Poly1305 construction with a 4-byte truncated Poly1305 tag (HomeKit-specific), so open composes the chacha20 and poly1305 component crates rather than the 16-byte aead.

Structs

BroadcastKey

A 32-byte ChaCha20-Poly1305 key for decrypting encrypted broadcast notifications. Zeroized on drop; its Debug is redacted.