prekeys
A prekey in cryptography is a public key that is generated in advance and published so that others can initiate a secure session with the key owner even if the owner is offline. The corresponding private key remains with the owner and is used later to complete the key exchange.
In modern messaging protocols, a prekey is part of a bundle that a user uploads to a
To initiate a session, the sender downloads the recipient’s prekey bundle and performs a key exchange using
Security and lifecycle considerations include generating prekeys on the device, rotating keys to limit exposure, and