Preshared keys are created by an administrator on one system. The keys are then shared out of band with administrators of remote systems. You should take care to create large random keys and to protect the file and the out-of-band transmission. The keys are placed in the /etc/inet/secret/ike.preshared file on each system. The ike.preshared file is for IKE as the ipseckeys file is for IPsec. Any compromise of the keys in the ike.preshared file compromises all keys that are derived from the keys in the file.
One system's preshared key must be identical to its remote system's key. The keys are tied to a particular IP address. Keys are most secure when one administrator controls the communicating systems. For more information, see the ike.preshared(4) man page.