This post is a bit technical and isn’t for everyone. I still want to include it in Fraudo.com because it could help someone, someday.
MS-CHAP v2 is an authentication protocol used to secure VPNs and some wireless networks. It’s commonly used with PPTP VPNs and sometimes with WPA2 wireless networks. For the past few years it was considered secure as long as it’s used with a strong password (a complicated password).
Today some researchers at a security conference demonstrated how to crack it in one day. They demonstrated that they can decrypt all data sent across the VPN or over WiFi.
So if you’re setting up a network and come across the MS-CHAP v2 setting, remember that as of today it’s no longer secure. It’s not even slightly secure, or better than nothing. If someone wants to view your encrypted VPN or WiFi traffic and you use MS-CHAP v2 then they can, with very little effort. Full details on cracking MS-CHAP v2 are here.