> For the complete documentation index, see [llms.txt](https://docs.vida.id/identity-stack/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vida.id/identity-stack/authentication/introduction/authentication-services.md).

# Authentication Services

VIDA offers a suite of authentication solutions designed to protect transactions and user data. Combining device-based security and advanced biometric technology, VIDA ensures that every action on your platform is verified and secure.

## **Authenticators**

Authenticators are the means by which users prove their identity to an authentication server. These authenticators are categorized into three classes:

* **Something you know:** Knowledge-based factors like passwords, PINs, or patterns.
* **Something you have:** Possession-based factors such as device tokens, mobile push notifications, or digital certificates.
* **Something you are:** Biometric authentication factors, such as face recognition or fingerprint scanning.

<figure><img src="/files/oBkGcdsksgETWOIwJoA9" alt=""><figcaption></figcaption></figure>

A strong multi-factor authentication strategy combines authenticators from different classes.&#x20;

For example, pairing a PIN with a Phone Token or using a Face Token provides enhanced security.

### **VIDA Phone Token**

A **device-centric authenticator** that leverages **Public Key Infrastructure (PKI)** to bind a unique private key to each registered device.

* **Key Features:**
  * The private key is securely stored within the device.
  * Ensures that only trusted devices can perform secure transactions or access sensitive data.

<figure><img src="/files/eCjQxLFoh4kXyu9lItNu" alt=""><figcaption></figcaption></figure>

### **VIDA Face Token**

A **biometric authentication factor** that ensures transactions are performed by a **verified user** on a **trusted device** by combining:

* Phone Token (Device Authentication)
* Facial Recognition (Identity Verification)
* Liveness Detection (Spoof Prevention)

**Key Features:**

* **Live Biometric Matching** – Securely matches the user’s **live selfie** against their **pre-registered biometric data**.
* **Device Binding via PKI** – Uses **Public Key Infrastructure (PKI)** to bind biometric data to a **trusted device**, preventing unauthorized use.
* **Multi-Factor Authentication** – Ensures that both the **user's identity** and **device authenticity** are verified before approving transactions.

<figure><img src="/files/moYwNimt0x6O4JXKqCSf" alt=""><figcaption></figcaption></figure>

### **VIDA Face Match**

VIDA Face Match enhances security by verifying the user's identity through **facial recognition**. It compares the user’s live facial image against their **biometric data** to ensure that the transaction is being performed by the **authorized individual**.

**Key Features:**

* **Real-Time Facial Verification** – Matches the user’s face against their stored biometric profile.
* **Passive User Experience** – Seamlessly integrates into authentication flows without disrupting the user journey.