---
title: "RADIUS back-end authentication"
slug: "oas-ag-radius-back-end-authentication-3-27"
updated: 2025-07-04T10:04:40Z
published: 2025-07-07T14:23:08Z
canonical: "docs.onespan.com/oas-ag-radius-back-end-authentication-3-27"
---

> ## 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.

# RADIUS back-end authentication

OneSpan Authentication Server can pass RADIUS return attributes from the back-end server to the client component. Back-end authentication is supported with the following protocols:

- PAP
- CHAP
- MS-CHAP
- MS-CHAP v2 with MPPE key generation

For more information about authentication using RADIUS topologies, see [RADIUS](/sec/docs/oas-ag-radius-3-27).