Authentication is performed on a plurality of links to be used to couple one node of the computing environment and another node of the computing environment. The performing authentication includes obtaining, by the other node from the one node via one link of the plurality of links, an identifier of a shared key maintained by a key server. The other node uses the identifier to obtain the shared key from the key server. An indication that the other node decrypted a message received from the one node using the shared key is sent from the other node via the one link. The sending the indication on one or more other links of the plurality of links is repeated for subsequent messages decrypted by the other node using the shared key previously obtained.