Re: CARD: Details on signing unsolicited CARD Reply messages

On Fri, 10 Oct 2003, Marco Liebsch wrote:
>
> The issue of authentication of advertised messages is common to many
> other protocols. The question is whether or not the CARD protocol spec
> sould be specific to a solution. If there are more efficient solutions
> in the future, why not keeping the flexibility to adopt the CARD
> protocol to that mechanism?

IMO, if you have a mechanism such as the unsolicited multicast replies,
which cannot be secured with standard security protocols, then the
security mechanism should be specified in the protocol spec for
interoperability. If interoperability is not needed, then it can be left
open.

Vijay's suggestion, to just say that the mechanism is not defined here,
might be an easy way to handle this issue and maybe sufficient for an
experimental RFC.

> But I am also fine with adding some more details here. Any
> proposals for details on a mechanisms?

You could look at how TLS does this and use some PKCS standard with RSA.
This would still leave open how MN learns the public key of AR.

Henrik