Re: [MMUSIC] Where to apply encryption?

Yes.  Back in the days of the ZRTP / DTLS wars, the possibility of just
using DTLS was discussed, but morphed into DTLS-SRTP for the reasons Martin
describes.

On Wednesday, February 27, 2013, Martin Thomson wrote:

> There are no security reasons why this wouldn't work.  Some
> applications already do this.
>
> The actual problems are manifold:
>
>  - SRTP was designed to have a low per-packet overhead.  The DTLS
> record layer has a larger per-packet overhead.
>  - SRTP exposes certain attributes in clear text for intermediaries to
> use.  Intentionally.  Using DTLS would lose this.
>  - SRTP enjoys wide support.  This would harm interoperability with
> existing communication devices, forcing the use of more complex
> gateways.
>
> --Martin
>
> On 27 February 2013 13:58, Dale R. Worley <worley@ariadne.com<javascript:;>>
> wrote:
> > Current bundling proposals seem to expect that the packets on the wire
> > will be either SRTP/SRTCP or SCTP-within-DTLS.  Of course, this
> > provides encryption of the carried media.
> >
> > But it seems to me that it would be more straightforward to multiplex
> > RTP/RTCP and SCTP packets, and than as a lower layer, have one DTLS
> > association that encrypts all of those packets indifferently.  It
> > would also provide privacy regarding the number and types of the
> > bundled media streams.
> >
> > But my knowledge of crypto is thin, and maybe there's a reason that
> > using one DTLS association to encrypt the multiplexed packet stream
> > wouldn't work as well.
> >
> > Dale
> > _______________________________________________
> > mmusic mailing list
> > mmusic@ietf.org <javascript:;>
> > https://www.ietf.org/mailman/listinfo/mmusic
> _______________________________________________
> mmusic mailing list
> mmusic@ietf.org <javascript:;>
> https://www.ietf.org/mailman/listinfo/mmusic
>