Zrtp

VoIP security architecture in brief

November 21, 2013

Voice over IP (VoIP) has been around for a long time. It’s ubiquitous in homes, data centers and carrier networks. Despite this ubiquity, security is …

Threats and Usability of Secure Voice

July 10, 2012

In my previous post I found that end-to-end encryption with OSTN is both effective and usable. There are two important things the user must be aware …

A Network Analysis of Encrypted Voice over OSTN

July 5, 2012

Introduction to OSTN The OSTN network stands for Open Source Telephony Network. It is a federated network standard for supporting Internet calling …

<!--:en-->OSTN secure VoIP wizard now built into CSipSimple for Android<!--:-->

May 26, 2012

If you saw our last post about how to setup your own secure voice-over-IP server instance, then this news is for you. If you are an Android user …

<!--:en-->Build your own Open Secure Telephony Network, some assembly required<!--:-->

May 17, 2012

The Open Secure Telephony Network is a standard that defines how to configure a VoIP softswitch with the capability to have secure two-way VoIP …

Singing and Dancing for Encryption

April 19, 2012

If you see me dancing or singing with my phone in my hand, I may not just be having a great time, but also creating an encryption key. Part of the …

Call My Email

March 22, 2012

What if you could call me directly through my email? No exchanging of phone numbers or searching for handles on Skype. Just plain and simple email. …

Acrobits Groundwire – OSTN supports iPhone

March 21, 2012

The Guardian Project develops open source software primarily for the Android platform but we strive for security by design to be a part of all …

Free SIP Providers with ZRTP support

February 22, 2012

This post is part of a series on our work researching the Open Secure Telephony Network. After you have CSipSimple installed on your mobile handset, …

Open Source SIP Client for Android

February 22, 2012

The first step in the Open Secure Telephony Network (OSTN) is a client. We can’t make a phone call without a phone. In this case there are three …