Remember EKU
Full name: Extended Key Usage
Memory aid: Extend the certificate's Key-Usage purpose list.
EKU and the Key Usage extension express different constraints.
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
EKU — Extended Key Usage
Constrains a certificate's permitted application purposes.
Why learn EKU — Extended Key Usage?
Constrains a certificate's permitted application purposes.
Where it came from
EKU and the Key Usage extension express different constraints.
- Memory aid (a learning cue, not the expansion): Extend the certificate's Key-Usage purpose list.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Without looking, expand EKU: Extended Key Usage.
- Recall this memory aid: Extend the certificate's Key-Usage purpose list.
- Explain the practical use: Constrains a certificate's permitted application purposes.
- Explain this distinction: EKU and the Key Usage extension express different constraints.
- Identify EKU in a device specification, architecture diagram, or system inventory.
Documentation and sources
- IETF RFC 5280 (www.rfc-editor.org)