Zfone: Secure Cross-Platform Voice Communication for Linux
This article discusses privacy threats (both governmental and criminal) to VoIP communications on the Internet, and examines an option for dealing with these issues: Zfone.
I provide a detailed installation and setup walkthrough for the Debian and Ubuntu Linux distributions: where to get Zfone, how to build the Zfone beta from the source tarball, how to get and install the dependencies from the Debian or Ubuntu repositories, and how to make the program run at startup for both the KDE (3.5.x) and Gnome Linux window managers. We'll also take a brief look at router and firewall setup for Gizmo, the specific VoIP package used to demonstrate Zfone's functionality.
Once you've followed these instructions, all you need to do to ensure secure VoIP communications on the Net is to run your VoIP software; the zfoned background daemon and Zfone user application will already be running.
Why You Need Secure Internet Communication
Do you use VoIP to discuss confidential business or personal topics? Voice communication over the Internet has the same privacy issues that email has. When you communicate via the Internet, you not only entrust your content to the person with whom you're communicating, but also every single person and business in a position to intercept your packets—either legitimately or illegitimately—as well as the federal government.
You're also trusting that nobody has managed to get any wiretapping malware onto your machine (or any computer on your LAN) that's capable of intercepting VoIP communication. For most people, given the amount of malware floating around and the probability that there's at least one Windows computer on your LAN, this is probably a more serious threat.
The only effective way to protect your communications privacy online is via high-quality encryption. Zfone is a solution to this problem, handling voice and video (in some videoconferencing VoIP applications) by effectively converting VoIP clients into secure phones.