---
type: source
title: "Matrix Privacy Policy - URZ"
tags: [privacy, gdpr, matrix, data-protection]
related: [matrix-datenschutz, matrix, matrix-id]
created: 2026-06-30
updated: 2026-06-30
authors: []
year: 2026
url: "https://rz.uni-greifswald.de/dienste/allgemein/instant-messaging-chat/matrix/datenschutz"
venue: "Universitätsrechenzentrum (URZ)"
sources: ["output/rz_uni_greifswald_de_dienste_allgemein_instant_messaging_chat_matrix_datenschutz.md"]
---

# Matrix Privacy Policy - URZ

This source document outlines the data processing information for the Matrix instant messaging service provided by the Universitätsrechenzentrum (URZ) at the Universität Greifswald, in accordance with Articles 13 and 14 of the GDPR (DSGVO).

## Key Provisions

### Data Processing and Legal Basis
- **Voluntary Use**: The service is optional and requires explicit consent via the account management system.
- **Legal Basis**: Processing is based on user consent according to Art. 6 Abs. 1 lit. a DSGVO.
- **Processed Data**: Includes Matrix-ID, name, email, IP address, client/browser information, session data, communication partner details, and the content of messages.

### Retention and Deletion
- **Log Data**: Deleted after 7 days.
- **Personal Data**: Generally deleted upon request or when the user leaves the university.
- **Matrix-ID Exception**: The Matrix-ID is technically permanent and cannot be deleted to prevent duplicate assignments. To mitigate this, the URZ uses randomly generated numbers for IDs, ensuring they are anonymized once the account is deleted.
- **Room Persistence**: Communication data in a room is only deleted from the university server once *all* participants have left the room.

### External Communication
- **Federation**: Data is processed on external servers when communicating with external Matrix users.
- **Lack of Control**: The Universität Greifswald has no influence over the data retention or deletion policies of external Matrix servers.

## Responsible Parties
- **Controller**: Universität Greifswald, represented by Rector Prof. Dr. Katharina Riedel.
- **Data Protection Officer**: Dominique Lenzner (SIS - Schweriner IT- und Servicegesellschaft mbH).
- **Supervisory Authority**: Landesbeauftragte für Datenschutz und Informationsfreiheit Mecklenburg-Vorpommern.