Having a look at various vpn standards

PPTP

Simply because it employs 128 bit keys to safe traffic, PPTP or Point-to-Point Tunneling Protocol is thought to be a much less secure method compared to people. Nevertheless, for a large amount of people, this will already perform, particularly when they talk with a VPN just for private use.

L2TP

An even more reliable decision is Layer 2 Tunneling Protocol or L2TP, because it works along with IPSec project which uses better protected encryption methods than what's used with PPTP. The mixture of the 3DES encryption algorithm along with a 168 bit keys are precisely what create L2TP encryption stronger.

SSTP

Secure Socket Tunneling Protocol or SSTP is undoubtedly the most protected of all practices, since it is a SSL VPN protocol, and uses 2048 bit encryption keys, along with validation certificates.

You should have a look at some vpn reviews to get additional information