[ipv6hackers] opportunistic encryption in IPv6

[Jim Small]

Hi Mark,

> >>  > The fundamental challenge for encryption is key distribution and
> >>  management:
> >>  > * How do I authenticate the intended recipient(s)?
> >>  > * How do I distribute a key without letting anyone except the
> >> intended recipient(s) get it?
> >>
> >>  DH pretty well solves this, no?
> >
> > Yes and no.  DH is a good answer, but IKE/IPsec still requires
> > pre-shared keys or RSA key pairs to start with.
> 
> Don't think so anymore.
> 
> "Better-Than-Nothing Security: An Unauthenticated Mode of IPsec"
> http://tools.ietf.org/html/rfc5386

Thanks - I was not aware of that.  So BTNS is interesting - but it doesn't solve the above problems.  Per the RFC, BTNS doesn't authenticate peers.  It would seem that secure key distribution (maintain confidentiality, integrity, and authentication) remains a vexing problem.

Here's an interesting question more relevant to the list and the paper though - are IPv6 CGAs useful?  It seems like SeND is dead.  But does anyone on the list think that CGAs could provide a useful competitive advantage for IPv6 over IPv4?  Are these a useful building block?  One thing I wonder about is a 64 bit hash is pretty small - I wonder if that is sufficiently complex to provide security for the coming decade+?  PKI CAs using SCEP for enrollment/management work pretty well.  If you could get a key pair from DHCP or as a function of using a directory service, use it to generate a CGA, and then use that just for authentication it would already be fantastic.  Just being confident that an address is authentic and not spoofed is a huge improvement over the current state for Internet security.

Thoughts?
  --Jim