Other than a posting by Craig Southeren there has been little
discussion on
the end-user environment in which secure RTP will be deployed. VoIP
systems
are deployed in environments where the end-users expect them to
"just work",
users are far less tolerant of what in their mind are intruding
details than
users of web and email systems, even when those users are the same
people. A
lifetime's experience with the PSTN means that VoIP users just want
to pick
up the phone, dial and get connected.
The majority of those calls will be about non confidential matters,
but when
more sensitive issues are discussed users want a simple check that
their
conversation is secured end-to-end, the ZRTP SAS provides this in a
form
that is easy for the average end-user to understand. For the end-
user the
SAS is the analogue of the light on the phones used in cold-war spy
movies,
the light flashed when the line was secure.
To declare an interest, Borderware is implementing ZRTP using Phil's
toolkit. This protocol was chosen because of its ease of use and
because it
provides exactly what is needed to encrypt a VoIP call, ephemeral keys
negotiated without the overhead and complexity of certificate
management.
While not minimising the importance of getting the protocol details
right,
factors like end-user acceptance, ease of use and ease of
implementation are
also important. From this point of view ZRTP gets my vote.
------------------------------------------------------------------
Peter Cox Phone: +44 20 8759 1999
CTO International Fax: +44 20 8757 1998
Borderware Technologies Inc http://www.borderware.com