[VOIPSEC] Key Negotiation for SRTP
dwing at cisco.com
Sat Aug 27 03:05:07 BST 2005
> So my bottom line of this discussion so far is (for someone
> who wants to implement this in a few MB):
> 1. Implement SRTP
> 2. Put the keys for SRTP in the SDP, probably with the
> a=crypto line(s)
> 3. Use either TLS or S/MIME to make the key exchange secure/private.
> Even if someone uses an insecure transport protocol for sending the
> keys, that's a start. At least it does not reduce the security level.
> Hey lets think a little bit strategically here. Lure the implementors
> with SRTP and the crypto line, cuz that can be done relatively easily.
> Then step number three will come automatically later. Jumping over the
> mikey wall right from the beginning seems to be pretty hard to me. And
> in the end everybody has to implement TLS anyway.
I don't believe any standards organization would approve a recommendation
for implementors to do (2) -- send encryption keys over an unencrypted
> Having several conflicting proposals is not a good situation.
> It will help those people who want to see SIP dead.
I honestly don't know how to reduce this set of conflicting proposals:
1. Security Descriptions (draft-ietf-mmusic-sdescriptions)
2. MIKEY with null encryptor (RFC3830)
3. MIKEY with pre-shared keys (RFC3830)
4. MIKEY with RSA (public key) (RFC3830)
5. MIKEY with DH (RFC3830)
6. MIKEY with DHHMAC (draft-ietf-msec-mikey-dhhmac)
7. MIKEY with ECIES (draft-ietf-msec-mikey-ecc)
8. MIKEY with ECMQV (draft-ietf-msec-mikey-ecc)
9. MIKEY with RSA-R (draft-ietf-msec-mikey-rsa-r)
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