Encryption communication system capable of reducing network managing workload

Abstract

In an encryption communication system, an encrypt key ID of an encrypt apparatus appearing on a communication path between terminals is acquired by using a key seek packet, and an encrypt key ID is automatically learned based upon a key seek response packet for notifying the acquired encrypt key ID. As a result, communication data between the terminals are encrypted/decrypted, transparently relayed, and discarded by the respective encrypt apparatuses. Even when a communication network is made large and complex, the network for the encrypt communication can be readily managed.