Final answer:
The method described is public-key encryption or asymmetric encryption, where each server is configured with a public/private encryption key pair and identified by a host key fingerprint.
Step-by-step explanation:
The method described in the question is known as public-key encryption or asymmetric encryption.
In this method, each server is configured with a pair of keys - a public key and a private key. The method described is public-key encryption or asymmetric encryption, where each server is configured with a public/private encryption key pair and identified by a host key fingerprint.
The public key is used to encrypt data that can only be decrypted using the corresponding private key. The host key fingerprint serves as a unique identifier for each server.