Re: [Linphone-users] hardware with secure key for linphone

[David Kuehling]

>>>>> "Louis" == Louis Holbrook <address@hidden> writes:

> David, wouldn't the device still be creating the key material though?
> And potentially however are in control of that hardware would be able
> to compromise that key material and access backdoor? Whether the
> server is here or there won't change that?

> I'm thinking of end-to-end encryption here, of course.

With TLS+SRTP(SDES) there is no proper end-to-end encryption and this is
what I'm used to (and that's the state-of-the art with the hardware
phones I know/own).  How a proper end-to-end encryption protocol like
ZRTP integrates with use of an intermediate SIP media server, I don't
know.

But what I suggested amounts to using the SIP media server as one end of
the link and do end-to-end encryption betwen the media server and your
peers.  Your hardware SIP phone could even use totally unencrypted SIP
protocol talking to the server, which isn't a problem if you can trust
your local network.

End-to-end encryption is usually employed so that you can analyze the
security properties of a system without having to think about security
aspects of all the middlemen in the network.  However, if you cannot
trust your endpoint (your hardware phone) that doesn't really make
sense.  You may get a system with higher security guarantees by just
isolating the untrusted phone and doing the encryption somewhere else.

David