This XK0-005 practice question tests your understanding of security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A system administrator wants to encrypt a large directory of files using GPG with a symmetric cipher. Which two steps are necessary? (Select TWO).
gpg --decrypt file.gpg
Why wrong: This decrypts, not encrypts.
Use a passphrase to encrypt
Symmetric encryption requires a passphrase.
gpg --encrypt --recipient user file
Why wrong: This is asymmetric encryption requiring a public key.
Import a public key
Why wrong: Public keys are used for asymmetric encryption.
gpg --symmetric --cipher-algo AES256 file
This encrypts the file symmetrically with AES256.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Use a passphrase to encrypt
Option B is correct because symmetric encryption in GPG requires a passphrase to derive the encryption key. When using `gpg --symmetric`, the cipher key is generated from a passphrase provided by the user, making the passphrase the essential secret for both encryption and decryption. Without a passphrase, symmetric encryption cannot proceed.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
gpg --decrypt file.gpg
Why it's wrong here
This decrypts, not encrypts.
Use a passphrase to encrypt
Why this is correct
Symmetric encryption requires a passphrase.
Related concept
Read the scenario before looking for a memorised answer.
gpg --encrypt --recipient user file
Why it's wrong here
This is asymmetric encryption requiring a public key.
Import a public key
Why it's wrong here
Public keys are used for asymmetric encryption.
gpg --symmetric --cipher-algo AES256 file
Why this is correct
This encrypts the file symmetrically with AES256.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
The trap here is that candidates confuse symmetric encryption with asymmetric encryption and select `--recipient` or public key import, not realizing that `--symmetric` requires only a passphrase, not a key pair.
Detailed technical explanation
Under the hood, `gpg --symmetric --cipher-algo AES256` uses a key derivation function (S2K, String-to-Key) to convert the passphrase into a 256-bit AES key. The encrypted file is stored in the OpenPGP message format (RFC 4880), which includes a symmetric-key encrypted session key packet. In real-world scenarios, this is ideal for encrypting large directories because it avoids the overhead of managing recipient public keys and allows a single shared passphrase for decryption.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the XK0-005 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
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FAQ
Security — This question tests Security — Read the scenario before looking for a memorised answer..
The correct answer is: Use a passphrase to encrypt — Option B is correct because symmetric encryption in GPG requires a passphrase to derive the encryption key. When using `gpg --symmetric`, the cipher key is generated from a passphrase provided by the user, making the passphrase the essential secret for both encryption and decryption. Without a passphrase, symmetric encryption cannot proceed.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This XK0-005 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 XK0-005 exam.
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