We do not currently know of any antonyms for pre-shared key.
The noun pre-shared key is defined as:
A TKIP passphrase used to protect your network traffic in WPA. A mechanism in Wi-Fi Protected Access (WPA)—Personal that allows the use of manually entered keys or passwords to initiate WPA security. The PSK is entered on the access point or home wireless gateway and each PC that is on the Wi-Fi network. After entering the password, Wi-Fi Protected Access automatically takes over. It keeps out eavesdroppers and other unauthorized users by requiring all devices to have the matching password. The password also initiates the encryption process which, in WPA is Temporal Key Integrity Protocol (TKIP) and in WPA2 is Advanced Encryption Standard (WPA2).
