PPTP encryption uses MPPE 128 bit cipher with or without compression and MS-CHAPv2 authentication.
L2TP encryption uses the standardized IPSec protocol either the 3DES or AES encryption algorithm. A 256-bit key will be used for encryption.
OpenVPN protocol uses AES cipher with 128-bit and 256-bit (Optional) encryption, hash algorithm is 160bit SHA1, control channel is TLSv1/SSLv3 DHE-RSA-AES256-SHA and 2048 bit RSA.
SoftEther VPN protocol uses AES256 cipher encryption algorithms to protect the VPN tunnel from attackers and information thieves on the Internet. A user can choose which cipher algorithms to be used.