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From: Gregory Maxwell <greg@xiph.org>
Date: Fri, 1 Jun 2018 04:15:13 +0000
Message-ID: <CAAS2fgRS=NXgSBQinci6umHu=X9SxDL-GMkYomhB93PHv1_suQ@mail.gmail.com>
To: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [bitcoin-dev] BIP 158 Flexibility and Filter Size
Precedence: list

On Fri, Jun 1, 2018 at 2:52 AM, Olaoluwa Osuntokun via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:
> One notable thing that I left off is the proposed change to use the previous
> output script rather than the outpoint. Modifying the filters in this
> fashion would be a downgrade in the security model for light clients, as it

Only if you make a very strong assumption about the integrity of the
nodes the client is talkign to. A typical network attacker (e.g.
someone on your lan or wifi segmet, or someone who has compromised or
operates an upstream router) can be all of your peers.

The original propsal for using these kinds of maps was that their
digests could eventually be commited and then checked against the
commitment, matching the same general security model used otherwise in
SPV.

Unfortunately, using the scripts instead of the outpoints takes us
further away from a design that is optimized for committing (or, for
that matter, use purely locally by a wallet)...