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From: Gregory Maxwell <greg@xiph.org>
Date: Tue, 29 May 2018 03:24:45 +0000
Message-ID: <CAAS2fgR+tTbS+X=HiYzjPtgyrtGyN-RsPQrp=gknTHsNR=fMpQ@mail.gmail.com>
To: Jim Posen <jim.posen@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP 158 Flexibility and Filter Size
Precedence: list

On Tue, May 29, 2018 at 2:42 AM, Jim Posen <jim.posen@gmail.com> wrote:
> Certain wallets may be able to use only the output script filter by using
> output scripts to watch for confirmations on sent transactions, assuming
> that application is the only one with access to the private keys. The
> additional benefit of the input script/outpoint filter is to watch for
> unexpected spends (coins getting stolen or spent from another wallet) or
> transactions without a unique change or output address. I think this is a
> reasonable implementation, and it would be nice to be able to download that
> filter without any input elements.

In this configuration there is little need to access historical blocks
though, since you're assuming that you'll never recover from a backup.
No?