Understanding known_hosts | LinuC Level 1 102 Exam original practice question

1.10.3Basic

An SSH client compares a previously seen server host key with the key presented now.

Which file stores this comparison data?

Hint 1: Focus on the key relationship

Identify who must decrypt the data, then distinguish confidentiality, authentication, and the direction of each key operation.

Hint 2: Key terms

Review the short definitions of SSH keys, forwarding directions, encryption, and signatures involved.

known_hosts: The file that stores remote host keys for later comparison.
Host-key verification: The comparison of a presented server key with trusted recorded information.
authorized_keys: The server-side allow-list for a user's login public keys.
Host identity: Information used to establish which server a connection reached.
Key change warning: A warning raised when a host presents a key different from the recorded key.

Detailed explanation

Incorrect~/.ssh/authorized_keys

Correct. known_hosts records remote host keys.

Correct~/.ssh/known_hosts

Incorrect. authorized_keys is server-side user-key authorization.

Incorrect~/.ssh/id_ed25519

Incorrect. id_ed25519 is the client's private key.

Incorrect/etc/shadow

Incorrect. /etc/shadow stores local authentication data.

An example you can run in a temporary verification environment.

printf '%s\n' '~/.ssh/known_hosts stores server host keys'

~/.ssh/known_hosts stores server host keys

Foundation review

A server identity key used by SSH clients to detect a changed endpoint.

A key pair used to authenticate a user to an SSH server.

An SSH tunnel that carries traffic between a local, remote, or dynamic endpoint.

Question IDKL-102-1153

EnvironmentOpenSSH clientのファイル役割

Last technical review2026-08-20

More practice in this area