Tunnel endpoints must be authenticated before secure VPN tunnels can be established. User-created remote-access VPNs may use passwords, biometrics, two-factor authentication or other cryptographic methods. Network-to-network tunnels often use passwords or digital certificates. They permanently store the key to allow the tunnel to establish automatically, without intervention from the administrator. Networking Tips + Tricks (Based On Your Purchases and/or Registered Products) HOW PRIVATE ARE VPNS? DO THEY LOG EVERYTHING I DO?