Re: [rtcweb] #30: Wiretapping

[Harald Alvestrand <[e-mail]>]

On 09/13/2013 02:08 AM, rtcweb issue tracker wrote:
> #30: Wiretapping
>
>  In several sections of the document, the phrase "It is essential
>  that the communication cannot be wiretapped [RFC2804]" is used.
>  The phrase is used in Sections 3.2.1.1, 3.2.11.1, 3.2.12.1, 3.2.13.1,
>  3.3.1.1 and 3.2.3.1, but not in 3.2.14.1 (which also does not
>  reference F20).
>
>  Given the recent revelations, and the discussion of SRTP/SDES at
>  IETF 87, I would suggest the following:
>
>  a. Use of more precise terminology than what is in F20.  For example,
>  I think what we are asking for in many of the F20 scenarios is
>  per-packet encryption and integrity protection of media,
>  utilizing keys known only by the endpoints, as well as support
>  for perfect forward secrecy.
I think this is a too low level of detail for an use cases document. It
does belong in the security / security-arch document, where we detail
both what the requirement implies and how the requirement is implemented.

If we want to add details here, I suggest adding "against an adversary
that has access to the signalling path and/or access to one of the end
systems after the communication has occured" (which would lead to a
requirement for DTLS key exchange and PFS).

>
>  b. Inclusion of a reference to F20 in Section 3.2.14.1 (Distributed
>  Music Band).  Not sure why protection against snooping wouldn't be
>  relevant in this use case (there are countries where musicians
>  have been severely punished).
>
>  c. Consideration of the requirement in gateway scenarios. For gateway
>  scenarios such as 3.3.1.1, the e2e key management
>  requirement probably isn't realistic, so maybe we need to
>  just cite F35/F36 for that case.
>
If we use the language I suggested above, noting that this spec can do
nothing to secure things beyond the gateway is probably enough ("e2e"
key management in this case would mean "end to gateway" - it's up to the
gateway and what's beyond it to protect the keys after that).


-- 
Surveillance is pervasive. Go Dark.