This Raspberry Pi project created by maker Angainor shows you how to build a two-factor authentication system using a Raspberry Pi Pico ...

However, convenient and free two-factor authentication can add a high level of security to your Raspberry Pi or other Linux-based projects.

There’s a serial modem and a USB to serial adapter involved, and a PPP daemon running on the Pi clone answers the incoming call, negotiates authentication, and does the NAT.

Here's how it works. Once the PoisonTap software is installed, the Raspberry Pi device becomes a miniature Linux computer that presents itself as an Ethernet network.