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  • Description

Tab 1

Zfone is a cross-platform encryption software for secure VoIP calls.

Zfone uses the ZRTP protocol to negotiate the cryptographic keys and consists of the Zfone libZRTP SDK and the Zfone application.

The application detects when a call starts, initiates a cryptographic key agreement between two parties and then continues to encrypt and decrypt voice packets during communication.


  • Runs in the Internet protocol stack on Windows, Mac OS X, Linux PC
  • Intercepts and filters all VoIP packets as they go in and out 
  • Compatible with a variety of VoIP clients 
  • Custom GUI for call protection notifications 
  • Keys destruction at the end of a call 
  • Keys agreements and management over the RTP packet stream
  • Auto-detection of the ZRTP support by the other VoIP client.

Zfone libZRTP SDK is available for developers to integrate into their VoIP applications.


  • Opportunity to add Zfone's ZRTP protocol to the VoIP applications
  • Used as an add-on for VoIP clients, firmware for VoIP telephones, VoIP PBX servers, mobile VoIP clients and SIP border control servers
  • Incorporation of VoIP application with ZRTP community for secure calls
  • Used for development of Zfone applications for Linux, Windows and Mac OS X, Windows CE and Symbian

Platform: C/C++
Unix: C, iptables, IP Queue, GTK Interface
MacOS: C, Cocoa, IPFW, Divert Sockets
Windows: C, Intermedia NDIS driver, Win API




VoIP solutions