GCIH Understanding Passwords Practice Question
Which of the following is an advantage of using a Key Derivation Function (KDF) like Argon2 over a simple hash like SHA-256?
⚠ Common exam trap
Candidates often assume KDFs are 'more complex' or 'encrypt the data better'. The primary advantage of KDFs like Argon2 is being 'memory-hard', which forces hardware to use more resources per guess.
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
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KDFs are memory-hard and resist GPU cracking
Standard cryptographic hashes like SHA-256 are designed for speed, which is a disadvantage when storing passwords because it allows attackers to test millions of guesses per second. KDFs like Argon2 are specifically designed to be slow and resource-intensive (memory-hard). By forcing the hardware to consume significant memory and time for every single hash calculation, KDFs make large-scale brute-force and dictionary attacks computationally expensive, providing much better security for sensitive credentials.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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KDFs are faster and improve login performance
Why it's wrong here
KDFs are intentionally slower than standard hashes. This slowness is exactly what makes them secure for password storage. If a KDF were faster, it would be less secure, as it would allow attackers to test more password guesses per second during an offline brute-force attack.
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KDFs are memory-hard and resist GPU cracking
Why this is correct
Argon2 is a memory-hard KDF, meaning it requires a significant amount of RAM to compute. GPUs have many cores but limited memory per core. This design makes it very difficult for GPUs to parallelize the hashing process, effectively negating their speed advantage and making cracking much slower.
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KDFs allow for reversible password recovery
Why it's wrong here
KDFs are one-way functions and do not allow for the reversal of a hash to obtain the original password. Password recovery mechanisms should always involve resetting the password, never recovering the existing one, because a system that allows password recovery implies that passwords are stored in a reversible format.
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KDFs require less storage space in the database
Why it's wrong here
KDFs typically require more storage space than standard hashes because they need to store parameters like the iteration count, memory cost, and the salt along with the hash output. Storage efficiency is not the goal; security through computational hardness is the primary design requirement for password KDFs.
About these practice questions
This GCIH question is part of Courseiva's 322-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 GCIH 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 GCIH exam.