Quiz Entry - updated: 2026.07.14
What are the three main protection mechanisms in cryptography and which security requirement does each address?
Encryption protects confidentiality, MACs/authentication protect data integrity, and authentication protocols protect user authenticity.
| Protection Mechanism | Security Requirement | How |
|---|---|---|
| Encryption (Verschlüsselung) | Confidentiality | Makes data unreadable to unauthorized parties |
| MAC / Authentication values (Authentikation) | Data Integrity & Authenticity | Detects modification, insertion, and enables non-repudiation |
| Authentication Protocols (Authentifizierungsprotokolle) | User Authenticity | Verifies the identity of communication partners |
Important: Encryption alone does NOT protect integrity. A ciphertext can be modified without the attacker knowing the plaintext — the receiver would decrypt to garbage but might not detect tampering. You need a MAC or signature for integrity.