Mac® Security Bible

12.2. VPN Varieties

Just as there are multiple protocols for transferring files over the Internet but with the same end result, there are numerous varieties of VPN, all of which aim to accomplish essentially the same thing. The protocols do differ in certain important details, however, and require somewhat different methods of configuration and use. This section covers only the most popular protocols — there are also a variety of others that you may occasionally encounter.

12.2.1. PPTP

Point-to-Point Tunneling Protocol, or PPTP, is a VPN protocol developed by Microsoft in association with several other vendors. It's by far the most commonly used type of VPN, and support for it is built into every major operating system, including Mac OS X and Windows. PPTP itself doesn't include encryption, but it's normally used along with an encryption protocol called Microsoft Point-to-Point Encryption (MPPE).

PPTP has a reputation for being insecure, although experts differ as to how legitimate that concern is. Early implementations of PPTP did in fact have a number of significant security holes, although most of those have been fixed and modern versions are far more secure than what was available a decade ago. As long as you choose a long, random password and keep it secure — and use the strongest possible encryption available with the particular version of PPTP to which you have access — it's difficult to show any significant specific security weakness. However, one caveat is that you may ...