GSEC Cryptography Application Practice Question
An organization needs to encrypt a database of PII. The requirements state that the encryption must be reversible by authorized staff and provide data integrity. Which implementation should the security engineer recommend?
⚠ Common exam trap
Candidates often select asymmetric encryption or simple hashing. They fail to realize that database encryption requires symmetric performance and that GCM provides the necessary integrity checking for data.
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
✓
Implement AES-256 in GCM mode.
Using AES-256 in GCM mode provides both confidentiality and authenticity. Symmetric encryption is appropriate for database encryption where authorized entities hold the decryption keys. GCM mode is preferred because it acts as an Authenticated Encryption with Associated Data (AEAD) algorithm, preventing unauthorized modification of the ciphertext. This is critical for database security, where verifying that data has not been tampered with is as important as preventing unauthorized disclosure of the stored information.
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 SHA-256 hashing for all database fields.
Why it's wrong here
Hashing is a one-way function used primarily for integrity verification or password storage, not for reversible encryption of PII. Since hashing cannot be reversed to retrieve the original data, it would render the database unusable for legitimate business processes that require authorized access to the underlying sensitive information.
- ✓
Implement AES-256 in GCM mode.
Why this is correct
AES-256 in GCM mode offers high-speed, symmetric encryption that ensures confidentiality while simultaneously providing integrity through an authentication tag. This approach satisfies the dual requirements of reversibility for authorized users and protection against data tampering, which is the gold standard for protecting sensitive database records in modern systems.
- ✗
Use RSA-4096 for encrypting large datasets.
Why it's wrong here
RSA is an asymmetric algorithm designed for key exchange or digital signatures, not for encrypting large volumes of data. Applying RSA to a database would be prohibitively slow and computationally expensive, as asymmetric operations are mathematically intensive compared to the symmetric algorithms designed for bulk data encryption tasks.
- ✗
Apply XOR-based encryption with a static global key.
Why it's wrong here
XOR encryption with a static key is extremely weak and provides no real security against even basic cryptanalysis. It is not considered a valid cryptographic solution in any professional context, as the lack of diffusion and the reuse of keys make the protected data trivially easy to decrypt.
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 |
About these practice questions
This GSEC question is part of Courseiva's 351-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official GIAC exam blueprint
This GSEC practice question is part of Courseiva's free GIAC 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 GSEC exam.