On the usability of OTR
Designing cryptosystems is not enough to ensure their adoption; they also need to be robust
and usable. OTR was not only published as an academic paper, but a library was provided
as well. OTR was designed to work over any existing Instant Message ( IM ) protocol with
any client that could incorporate the library, or plugin. Your favorite IRC client probably
has a plugin or library that can easily incorporate OTR. In this chapter, we will be using
OTR plugins that are built in the two IRC applications we will examine.
The design of OTR, specifically the perfect forward secrecy and deniability features, have
inspired derivates for other protocols besides real-time chatting. For example, Open Whis-
perSystems' TextSecure app for mobile devices uses an OTR-like protocol over SMS and
other asynchronous IM channels.
Also, OTR, like Tor and GPG, is recommended by the Freedom of the Press Foundation, a
U.S. Non-profit organization that supports and defends public interest journalism . This or-
ganization provides education and tutorials on how to use these tools. While presented in
the contexts of journalists protecting their sources, as Glenn Greenwald and Laura Poitras
used (Greenwald 2014), the information is applicable to any user of privacy enhancing