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LFCS · Question #395

An administrator can prevent dictionary based attacks against an OpenSSH server by forcing keybased authentication with which TWO parameters in sshd_config?

The correct answer is A. PasswordAuthentication D. PubkeyAuthentication. To prevent dictionary attacks on an OpenSSH server, an administrator should disable password authentication and enable public key authentication.

Submitted by packet_pusher· Apr 18, 2026Service Configuration

Question

An administrator can prevent dictionary based attacks against an OpenSSH server by forcing keybased authentication with which TWO parameters in sshd_config?

Options

  • APasswordAuthentication
  • BHostKey
  • CPrivatekeyAuthentication
  • DPubkeyAuthentication
  • EServerKey

How the community answered

(49 responses)
  • A
    92% (45)
  • B
    2% (1)
  • C
    2% (1)
  • E
    4% (2)

Why each option

To prevent dictionary attacks on an OpenSSH server, an administrator should disable password authentication and enable public key authentication.

APasswordAuthenticationCorrect

Setting `PasswordAuthentication no` disables password-based logins, eliminating the possibility of dictionary attacks against user passwords.

BHostKey

`HostKey` specifies the path to the server's host private key files and does not control authentication methods.

CPrivatekeyAuthentication

`PrivatekeyAuthentication` is not a standard `sshd_config` parameter; the correct parameter for key-based authentication is `PubkeyAuthentication`.

DPubkeyAuthenticationCorrect

Setting `PubkeyAuthentication yes` enables authentication using SSH keys, which are cryptographically strong and not susceptible to dictionary attacks.

EServerKey

`ServerKey` is not a standard `sshd_config` parameter; host keys are specified by `HostKey`.

Concept tested: SSHD authentication methods

Source: https://man7.org/linux/man-pages/man5/sshd_config.5.html

Topics

#SSH#sshd_config#Authentication#Security

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