---
type: entity
title: Elektronisches Zutrittskontrollsystem (eZKS)
tags: [security, access-control, infrastructure]
related: [multifunktionale-chipkarte, universitatsrechenzentrum-urz]
created: 2026-06-30
updated: 2026-06-30
sources: ["output/rz_uni_greifswald_de_dienste_allgemein_sonstiges_multifunktionale_chipkarte_zutr.md"]
---

# Elektronisches Zutrittskontrollsystem (eZKS)

The **Elektronisches Zutrittskontrollsystem (eZKS)** is the central electronic access control system used at the Universität Greifswald to manage entry to various buildings and restricted areas.

## Technical Architecture
The system utilizes a combination of online and offline locks to balance connectivity and accessibility:

- **Online Locks**: These are network-connected devices (typically found at main building entrances and barriers) that verify permissions in real-time against the central server and automatically update the data on the [[multifunktionale-chipkarte]].
- **Offline Locks**: These devices operate without a network connection and rely entirely on the data stored on the chip card. Because they cannot verify permissions in real-time, they require the card to have been updated by an online lock within the last **7 days**.

## User Feedback (LED System)
The eZKS locks provide visual feedback via LEDs:
- **Green**: Access granted.
- **Blue**: Card update in progress (only on online locks).
- **Red**: Access denied.
- **No light**: Indicates a temporary deactivation of the card due to too many errors in a short period. This typically resets automatically after 1-2 hours.

## Data and Privacy
The eZKS follows a data minimization approach:
- **On-Card Data**: Only a unique ID, access rights, and validity dates are stored on the card.
- **Central System**: Personal data (name, URZ username, department) is stored centrally and linked to the card's unique ID.
- **Logging**: The system logs when and where a card is used and whether technical updates were successful. These logs are used strictly for administrative purposes and are not used to create user profiles.
