Remember HKDF
Full name: HMAC-Based Key Derivation Function
Memory aid: HMAC first extracts, then expands Key material.
HKDF is not designed to slow password guessing like a password-hardening function.
Study area: Cryptography & trust · Batch 8
Relevant study for: CompTIA Security+ SY0-701 · ISC2 CISSP 2024 outline · ISC2 SSCP · CompTIA SecurityX · Cybersecurity Architect SC-100 · ISC2 CCSP · Security, Compliance, and Identity Fundamentals SC-900
Practice with exam flashcards →Cybersecurity & Identity / Knowledge library
HKDF — HMAC-Based Key Derivation Function
Derives keys using extraction and expansion based on HMAC.
Why learn HKDF — HMAC-Based Key Derivation Function?
Derives keys using extraction and expansion based on HMAC.
Where it came from
HKDF is not designed to slow password guessing like a password-hardening function.
- Memory aid (a learning cue, not the expansion): HMAC first extracts, then expands Key material.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Without looking, expand HKDF: HMAC-Based Key Derivation Function.
- Recall this memory aid: HMAC first extracts, then expands Key material.
- Explain the practical use: Derives keys using extraction and expansion based on HMAC.
- Explain this distinction: HKDF is not designed to slow password guessing like a password-hardening function.
- Identify HKDF in a device specification, architecture diagram, or system inventory.
Documentation and sources
- IETF RFC 5869 (www.rfc-editor.org)