PGP (Pretty Good Privacy) is a tool for data encryption. PGP is good to use for e-mails containing sensitive information. PGP can be downloaded from WWW and FTP at http://www.pgpi.com/.
An open source version of PGP is GPG (GNU Privacy Guard), which can be found at http://www.gnupg.org/.
There are primarily two tools for encrypted computer connections over the Internet: Kerberos and SSH.
Kerberos uses a central server that other computers use for verification. You must specify whether or not to encrypt files in each program that uses Kerberos. For more information on Kerberos, see http://web.mit.edu/kerberos/www/.
SSH does not use a central server; everything occurs on the two computers that are connected. An SSH connection encrypts everything; the password and all other traffic. X-Window System and Open-windows connections can be run with an SSH connection. For more information on SSH, see http://www.datafellows.com/products/.
An open source version of SSH is OpenSSH, which can be found at http://www.openssh.com/.
You can also purchase the extension module Ingate VPN to your Ingate Firewall. Ingate VPN enables you to create secure encrypted connections on an insecure network. See also http://www.ingate.com/vpn/.