potential new IETF WG on anonymous IPSec

Joe Touch touch at ISI.EDU
Sat Sep 11 00:00:08 PDT 2004


Bill Stewart wrote:

> At 12:57 PM 9/9/2004, Hal Finney wrote:
> 
>> >       http://www.postel.org/anonsec
>>
>> To clarify, this is not really "anonymous" in the usual sense.  Rather it
>> is a proposal to an extension to IPsec to allow for unauthenticated
>> connections.  Presently IPsec relies on either pre-shared secrets or a
>> trusted third party CA to authenticate the connection.  The new proposal
>> would let connections go forward using a straight Diffie-Hellman type
>> exchange without authentication.  It also proposes less authentication
>> of IP message packets, covering smaller subsets, as an option.
> 
> 
> I read the draft, and I don't see how it offers any improvement
> over draft-ietf-ipsec-internet-key-00.txt or Gilmore's proposal touse 
> "open secret" as a not-very-secret pre-shared secret
> that anybody who wants to can accept.

That is part of the solution, but not all, as noted below.

> It does introduce some lower-horsepower alternatives for
> authenticating less than the entire packet, and suggests
> using AH which I thought was getting rather deprecated these days,
> but another way to reduce horsepower needs is to use AES instead of 3DES.

That is corrected in  draft-touch-tcp-antispoof, which contains the BGP 
focus of anonsec-00; anonsec-01 (to appear in about 2 weeks) focuses on 
just the anonsec portion of 00.

> Also, the author's document discusses protecting BGP to prevent
> some of the recent denial-of-service attacks,
> and asks for confirmation about the assertion in a message
> on the IPSEC mailing list suggesting
>    "E.g., it is not feasible for BGP routers to be configured with the
>    appropriate certificate authorities of hundreds of thousands of peers".
> Routers typically use BGP to peer with a small number of partners,
> though some big ISP gateway routers might peer with a few hundred.
> (A typical enterprise router would have 2-3 peers if it does BGP.)
> If a router wants to learn full internet routes from its peers,
> it might learn 1-200,000, but that's not the number of direct connections
> that it has - it's information it learns using those connections.
> And the peers don't have to be configured "rapidly without external 
> assistance" -
> you typically set up the peering link when you're setting up the
> connection between an ISP and a customer or a pair of ISPs,
> and if you want to use a CA mechanism to certify X.509 certs,
> you can set up that information at the same time.

Thanks for that input; the claim that BGP in core Internet routers 
required intractible setup for TCP-MD5 has been refuted by experience 
noted during the TCPM WG meeting in San Diego as well. This section of 
tcp-antispoof will be updated accordingly.

Joe

> ----
> Bill Stewart  bill.stewart at pobox.com

[demime 1.01d removed an attachment of type application/pgp-signature which had a name of signature.asc]





More information about the cypherpunks-legacy mailing list