The primary design goal is ease of use. Usability issues have been a barrier in previous secure communication systems and have prevented wide spread adoption [3], [4]. PFC extends Facebook Chat so that users can continue to use their existing chat system that they are already familiar with instead of switching to a new secure chat system. Users will read
and compose messages with the added ability to designate when a chat session should be secure. The interface will
clearly illustrate the difference between a standard chat session and a secure chat session. The low-level details of how the
secure chat is implemented (e.g., key management, encryption algorithms) are handled transparently.