---
type: concept
title: Certificate Revocation
tags: [pki, security, certificates]
related: [dfn-pki-zertifikate, nutzerzertifikate, gruppenzertifikate, serverzertifikate, sectigo-portal]
created: 2026-06-30
updated: 2026-06-30
sources: ["output/rz_uni_greifswald_de_dienste_allgemein_speerung_von_zertifikaten.md"]
---

# Certificate Revocation

**Certificate Revocation** (Sperrung von Zertifikaten) is the process of invalidating a digital certificate before its official expiration date. This is a critical security measure used to ensure that a certificate can no longer be trusted if its security is compromised.

## Necessity of Revocation
The primary driver for revocation is the **compromise of the secret key** (private key). If an unauthorized party gains access to the private key, they could potentially impersonate the certificate holder or decrypt sensitive data.

## Revocation Procedures at URZ
For [[dfn-pki-zertifikate]] (including [[nutzerzertifikate]], [[gruppenzertifikate]], and [[serverzertifikate]]), the Universitätsrechenzentrum (URZ) offers two paths for revocation:

### 1. Self-Service via Sectigo Portal
Users can revoke their own certificates via the [[sectigo-portal]]. 
- **Prerequisite**: The user must have set a **Revocation PIN (Sperr-PIN)** during the initial application process.
- **Benefit**: Immediate invalidation without waiting for administrative processing.

### 2. Administrative Request
If a revocation PIN was not set or the portal is inaccessible, users must contact the URZ:
- **Ticket System**: Via the [[groupware]] ticket system.
- **Hotline**: Via the URZ central support hotline (ext. 1420).
