Pre-shared key

Pre-shared key

https://en.wikipedia.org/wiki/Pre-shared_key

In cryptography, a pre-shared key (PSK) is a shared secret which was previously shared between the two parties using some secure channel before it needs to be used.

To build a key from shared secret, the key derivation function is typically used. Such systems almost always use symmetric key cryptographic algorithms. The term PSK is used in Wi-Fi encryption such as Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), where the method is called WPA-PSK or WPA2-PSK, and also in the Extensible Authentication Protocol (EAP), where it is known as EAP-PSK. In all these cases, both the wireless access points (AP) and all clients share the same key.

预共享密钥，含义是保证的服务器段和客户均持有相同的密钥， 在加密和解密发生之前。

一般这种加密方式呗用于 无线加密  例如 WEP  WPA-PSK WPA2-PSK EAP-PSK

这种系统几乎总是使用对称加密算法， 例如 DES AES