Bill Stewart wrote:
At 12:57 PM 9/9/2004, Hal Finney wrote:
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@pobox.com
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