---
title: "Back-end authentication"
slug: "oas-ag-back-end-authentication-3-28"
updated: 2025-07-07T13:31:16Z
published: 2025-07-07T13:31:16Z
canonical: "docs.onespan.com/oas-ag-back-end-authentication-3-28"
---

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

# Back-end authentication

Back-end authentication describes the process of verifying user credentials with another system. It is used primarily to:

- Enable automatic management features, such as Dynamic User Registration (DUR) and authenticator self-assignment.
- Verify static passwords for users who do not have an authenticator and for Virtual Mobile Authenticator.
- Retrieve RADIUS attributes from a RADIUS server.
- Replace passwords to allow the user to log in with just a one-time password (OTP) in an environment where the Windows password is required (e.g. Outlook Web Access).