Authenticating communications between physical ports using knowledge of shared secrets

Techniques are provided for authenticating communications between physical ports using knowledge of shared secrets. One method comprises receiving, by a first entity, a connection request to establish a communication between physical ports of the first entity and a second entity; providing a first pseudo-random value to the second entity; obtaining a shared secret for communications with the second entity; generating a first hash value based on the shared secret and the first pseudo-random value; obtaining a second hash value from the second entity based on the shared secret and the first second pseudo-random value; and authenticating the communication in response to the first entity validating the first hash value using the second hash value. An encryption key based on the shared secret can protect communications between the physical ports of the first and second entities.