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SSCP Practice Question: A system administrator is configuring a file…
A system administrator is configuring a file encryption solution for a shared network drive. The solution must allow multiple users to read the files without sharing a single symmetric key. Which approach should be used?
⚠ Common exam trap
Many exam-takers choose Option B (direct public key encryption) because they understand asymmetric encryption but overlook the performance and practical limitations of encrypting large files with public key algorithms, which are designed for small data like keys.
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
✓
Encrypt the file with a symmetric key, then encrypt that key with each authorized user's public key
Describes hybrid encryption, which is the correct approach for this scenario. The file is encrypted with a random symmetric key (session key) for efficiency, and that symmetric key is then encrypted with each authorized user's public key. This allows multiple users to decrypt the symmetric key with their private key and then decrypt the file, without sharing a single symmetric key.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use a different symmetric key for each user and re-encrypt the file for each user
Why it's wrong here
This is inefficient and requires storing multiple encrypted copies.
- ✗
Encrypt the file with each user's public key directly
Why it's wrong here
Asymmetric encryption is too slow for large files.
- ✓
Encrypt the file with a symmetric key, then encrypt that key with each authorized user's public key
Why this is correct
This is a hybrid encryption approach that scales well and maintains security.
- ✗
Encrypt the file with a single symmetric key and share that key securely with all users
Why it's wrong here
Sharing a symmetric key among many users increases risk and management complexity.
Quick reference
Symmetric Encryption Algorithm Comparison
| Algorithm | Key Size | Block Size | Status | Notes |
|---|---|---|---|---|
| AES-128 | 128-bit | 128-bit | Current standard | NIST approved; WPA3, TLS |
| AES-256 | 256-bit | 128-bit | Current standard | Preferred for sensitive / govt data |
| 3DES | 112-bit effective | 64-bit | Deprecated (2023) | Replaced by AES |
| DES | 56-bit | 64-bit | Broken | Cracked in < 24 h; never deploy |
| ChaCha20 | 256-bit | Stream cipher | Current | TLS 1.3, WireGuard |
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SSCP practice question is part of Courseiva's free ISC2 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 SSCP exam.