---
type: source
title: "2FA Prerequisites: TOTP System Time Requirements"
tags: [2fa, totp, security, system-time]
related: [2-factor-authentication, totp]
created: 2026-07-01
updated: 2026-07-01
authors: []
year: 2026
url: "https://rz.uni-greifswald.de/support/dokumentation/anleitungen/2fa-mit-totp/2fa-voraussetzung"
venue: "Universitätsrechenzentrum (URZ) Documentation"
sources: ["output/rz_uni_greifswald_de_support_dokumentation_anleitungen_2fa_mit_totp_2fa_vorausse.md"]
---

# 2FA Prerequisites: TOTP System Time Requirements

This source outlines the critical technical prerequisite for using Time-based One-Time Passwords (TOTP) within the university's two-factor authentication system.

## Core Requirement: System Time Synchronization
The primary finding is that **TOTP codes are generated based on the system time** of the device running the authenticator application (such as [[keepassxc]] or [[freeotp]]). Consequently, if the device's system time is incorrect or has drifted, the generated codes will be invalid and will not be accepted by the authentication server.

## Verification and Remediation
The [[universitatsrechenzentrum-urz]] provides a specific tool to verify if a device's system time is correctly synchronized:
- **Verification URL:** `https://rz.uni-greifswald.de/wobinich/`

### Windows 11 Synchronization Steps
For users experiencing time drift on Windows 11, the following remediation process is recommended:
1. Open **Settings** (Windows Key + i).
2. Navigate to **Time & Language** $\rightarrow$ **Date & Time**.
3. Ensure **Set time automatically** is toggled to **On**.
4. Click the **Sync now** button under "Synchronize your clock".
