XK0-006 Security Practice Question
Which command can be used to generate an SSH key pair for user authentication?
⚠ Common exam trap
It's easy for candidates to confuse `ssh-keygen` (key generation) with `ssh-copy-id` (key deployment) or `ssh-add` (key loading), leading them to pick a command that manages existing keys rather than creating new ones.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
ssh-keygen
The `ssh-keygen` command is the standard tool for generating SSH key pairs (public and private keys) used for user authentication. It creates RSA, ECDSA, Ed25519, or DSA key files (e.g., `~/.ssh/id_rsa` and `~/.ssh/id_rsa.pub`) and supports options like `-t` for key type and `-b` for bit length, directly enabling passwordless login via public key authentication.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
ssh-keyscan
Why it's wrong here
ssh-keyscan gathers public host keys from remote hosts.
- ✓
ssh-keygen
Why this is correct
ssh-keygen generates SSH key pairs.
- ✗
ssh-copy-id
Why it's wrong here
ssh-copy-id copies public keys to remote hosts.
- ✗
ssh-add
Why it's wrong here
ssh-add adds private key identities to the authentication agent.
Quick reference
Asymmetric Encryption Algorithm Comparison
| Algorithm | Key Exchange | Signatures | Equivalent Security Key | Notes |
|---|---|---|---|---|
| RSA-3072 | Yes | Yes | 128-bit | Widely deployed; slow for bulk data |
| ECDSA P-256 | No | Yes | 128-bit | Fast signatures; standard TLS certs |
| ECDH / ECDHE | Yes | No | 128-bit | Perfect forward secrecy in TLS 1.3 |
| DH / DHE | Yes | No | 128-bit (3072-bit key) | Replaced by ECDHE in modern TLS |
| Ed25519 | No | Yes | ~128-bit | SSH keys, modern PKI |
Go deeper
Related to this question
Learn chapter
User and Group Administration
Key term
User
A user is any person, system, or device that interacts with an IT service, resource, or identity system, typically authenticated through credentials and authorized to perform specific actions.
Key term
SSH
SSH (Secure Shell) is a cryptographic network protocol that provides secure, encrypted communication and remote administration between two devices over an unsecured network.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This XK0-006 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the XK0-006 exam.