This parameter specifies the shared secret that will be used between this <ServerRADSEC> and RadSec clients that connect to it. The shared secret is used in the same way as Secret parameter in the Client clause: to encrypt passwords and generate message authenticators. The shared secret must be configured identically into <ServerRADSEC> and all RadSec clients that connect to it, regardless of whether TLS is enabled or not. An authentication error will occur if the shared secret is not correctly configured. For compliance with RFC 6614, the default value is radsec.