[VOIPSEC] Using SRTP for University project

[Randell Jesup]

Alan Johnston <alan at sipstation.com> writes:
>Last week at the IETF, Phil made an excellent argument in his 
>presentation that the encryption of media is none of the business of a 
>the signaling.  From an architectural point of view, tying the 
>encryption of media to the signaling is a bad idea.

True - it would have made more sense (in hindsight) if the encryption were
negotiated and keyed by direct end-to-end communication on the media
channel.  Downside - perhaps another roundtrip or two.  But this is moot
now unless we want to start defining this into an RTP variant, as Phil Z is
doing with ZRTP - except he's ignoring profiles and trying to transparently
piggyback it.  That has it's advantages, but there are disadvantages too.

>>All I meant was that you said you heard s/mime was not deployable - to which
>>I said if you want to get it through a service-provider's sip
>>infrastructure, it won't work.  Since the user has no power to change that,
>>other than not using service providers, their change of environment to
>>s/mime is not that useful. (Since it is probably the call through the
>>service-provider they're worried about the most)
>>
>>But yes, I definitely think there are some parts of the environment that are
>>practically impossible to change, to meet the needs/wants of everyone.
>>
>Users are going to demand confidentiality in their media sessions.  If a 
>service provider deploys an architecture in which they can not support 
>this, they will loose users to another service provider who has been 
>smart enough to use an architecture that allows end-to-end media encryption.

They may.  Users generally care only to a certain point.  Some aspects may
increase their sensitivity, like IP Videophones - people are much more
protective of their images in private calls than of their voice.
Especially people who grew up pre-web.  Obviously, businesses may have
other issues with tappable calls, and may even have fiduciary
responsibility to prevent it in certain industries.

-- 
Randell Jesup, Worldgate (developers of the Ojo videophone), ex-Amiga OS team
rjesup at wgate.com
"The fetters imposed on liberty at home have ever been forged out of the weapons
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