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ISC2 CC Practice Question: A company deploys a web application that stores…
A company deploys a web application that stores user passwords using a salted hash. During a security review, an auditor recommends switching from SHA-1 to SHA-256. What is the primary security benefit of this change?
⚠ Common exam trap
Many candidates confuse hashing with encryption — candidates see 'SHA-256' and pick 'encryption of passwords at rest' because both sound like data protection, but hashing is one-way and provides integrity/collision resistance, not confidentiality.
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
✓
It increases collision resistance
SHA-256 produces a 256-bit digest versus SHA-1's 160-bit digest, dramatically increasing the computational effort required to find two different inputs that hash to the same value. SHA-1 has known practical collision attacks (e.g., SHAttered in 2017), so migrating to SHA-256 strengthens the integrity of the stored password hashes against collision-based attacks. The salting still protects against rainbow tables, but the hash algorithm upgrade specifically addresses collision resistance.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
It improves system availability
Why it's wrong here
Availability concerns uptime and redundancy, which hashing algorithms do not affect. It is tempting because security reviews often bundle resilience findings, but the SHA-1 to SHA-256 change addresses collision resistance: SHA-1 collisions are practical, weakening the hash's ability to protect password integrity.
- ✗
It provides encryption of the passwords at rest
Why it's wrong here
Hashing is one-way and provides no confidentiality mechanism; encryption requires a cipher and key management. It is tempting because both protect stored credentials, but the SHA-1 to SHA-256 change only strengthens collision resistance, leaving the salted-hash storage model unchanged and passwords still not encrypted at rest.
- ✓
It increases collision resistance
Why this is correct
SHA-256 produces a 256-bit digest versus SHA-1's 160-bit output, raising the computational effort needed to find two inputs with identical hashes. This collision resistance gain is the primary benefit; salting already addresses rainbow-table and precomputation attacks.
- ✗
It enhances non-repudiation
Why it's wrong here
Non-repudiation requires digital signatures binding an identity to a message, which plain password hashing does not provide. It is tempting because both involve cryptographic primitives, but the SHA-1 to SHA-256 upgrade addresses collision resistance, not proof of origin or denial prevention.
Go deeper
Related to this question
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
Integrity
Integrity is the assurance that data has not been altered or tampered with in an unauthorized way, preserving its accuracy and consistency from source to destination.
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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 ISC2 exam blueprint
This CC 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 CC exam.