> ## Documentation Index
> Fetch the complete documentation index at: https://docs2.zenskar.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Two-factor authentication

## 1. Explanation: Understanding 2FA

This section explains the concepts behind authentication and why a second layer of security is necessary.

### Authentication vs. authorization

* **Authentication** verifies *who you are*.
* **Authorization** determines *what resources you can access* after your identity is confirmed.

### **Why use 2FA?**

Standard password-based authentication is vulnerable to brute-force attacks, phishing, and man-in-the-middle exploits. **Two-Factor Authentication (2FA)** is a type of Multi-Factor Authentication (MFA) that requires two different types of evidence to grant access. These factors usually fall into three categories:

1. **Something you know:** A password or PIN.
2. **Something you have:** A smartphone or a secure USB key.
3. **Something you are:** Biometrics like fingerprints or facial recognition.

By requiring a physical device (something you have) in addition to a password, 2FA ensures that even if an attacker steals your credentials, they cannot access your account without your secondary device.

***

## 2. Tutorial: Set up your first authenticator

Follow these steps to set up 2FA for the first time using a mobile application.

1. **Download an app:** Install either **FreeOTP** or **Google Authenticator** from your mobile device's app store.
2. **Log in:** Access your account on your computer. If 2FA has been enabled for your account by an admin, you will be prompted with a setup screen.
3. **Scan the QR code:** Open your chosen authenticator app, select the option to "Add a code" (usually a `+` icon), and point your camera at the QR code displayed on your computer screen.
4. **Verify the code:** The app will generate a 6-digit code. Type this code into the login screen on your computer and click **Submit**.
5. **Success:** Your account is now linked to your mobile device.

***

## 3. How-to guides: Managing 2FA

Practical steps for administrative and configuration tasks.

### How to enable 2FA for a user (Admin)

If you have administrative privileges, you can enforce 2FA for specific users:

1. Click the **drop-up menu** at the bottom-left corner (your profile name).
2. Select **Users** from the menu.
3. Locate the specific user in the list.
4. Click the **kebab menu** (three vertical dots) next to the user's name.
5. Select **Enable Two-Factor Authentication**.
6. Click **OK** on the confirmation prompt.

### How to manually configure an app

If your camera cannot scan the QR code, you can enter the details manually in your authenticator app using the parameters found in the **Reference** section below.

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## 4. Reference: Technical specifications

Detailed technical data for manual configuration and app comparison.

### Supported authenticator apps

| App                      | Developer | License     | Platform     |
| ------------------------ | --------- | ----------- | ------------ |
| **FreeOTP**              | Red Hat   | Open Source | Android, iOS |
| **Google Authenticator** | Google    | Proprietary | Android, iOS |

### TOTP configuration parameters

If manual entry is required, use the following Time-Based One-Time Password (TOTP) settings:

* **Type:** Time-based
* **Algorithm:** SHA1
* **Digits:** 6
* **Interval:** 30 seconds

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