RADIUS and VPN
A second factor for everything that speaks RADIUS.
VPN, firewalls, Wi-Fi controllers, network devices and Linux logins: the same Secret Squares and the same authenticator apps, without another product.
How a sign-in runs
The code comes from "Show grid" on the user’s PC or Mac, or from an authenticator app.
What it can do
A Windows service
It listens on UDP 1812 and answers any client that speaks RADIUS: VPN, firewalls, Wi-Fi controllers, network devices.
Three ways to ask
Two-step challenge (password, then code), password and code in one field, or code only.
Password check
Against Active Directory (LDAP) or against the user’s Twin Verify password.
Per-client groups and attributes
Different rules per client, and reply attributes such as VLAN, firewall groups and vendor attributes.
Blast-RADIUS protection
Protects against the Blast-RADIUS attack (CVE-2024-3596).
Codes from the user’s own device
"Show grid" in the tray or Mac menu bar, or an authenticator app. No hardware token.
Linux
SSH, sudo and su through pam_radius, with a setup script.
Good to know
So that your planning is right from the start:
- The Twin Verify service must be reachable: RADIUS sign-in does not work offline.
- It is its own RADIUS service, not an extension for the Microsoft Network Policy Server.

Ready for a sign-in people do not work around?
Tell us about your organisation and we will show you how Twin Verify fits. Write to us or call us.