 Pre-shared key

A Pre-shared Key (PSK) is a shared secret, typically a string of characters, used in cryptographic protocols for authentication. This key is known by both the client and the server before the secure communication starts. PSKs are commonly used in various security protocols, including: 1. **Wi-Fi Security**: In Wi-Fi networks, PSKs are often used in WPA (Wi-Fi Protected Access) and WPA2 for securing the network.

An overview of what you can do with a pre-shared key with tradeoffs can be found at: quantumcomputing.stackexchange.com/questions/142/advantage-of-quantum-key-distribution-over-post-quantum-cryptography/25727#25727 The options are: