To: Jonas Schnelli <dev@jonasschnelli.ch>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
References: <201608232012.12588.luke@dashjr.org>
	<90bf12f2-e109-28b4-e93e-54bbc8002cb4@electrum.org>
	<57BDACB2.9040307@jonasschnelli.ch>
From: Jochen Hoenicke <hoenicke@gmail.com>
Message-ID: <278c940d-4b3b-2b8a-1aa5-f0991f1e6c8e@gmail.com>
Date: Wed, 24 Aug 2016 16:42:25 +0200
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Subject: Re: [bitcoin-dev] BIP Status updates (including to Active/Final
 Status) - BIP 39, BIP 43, BIP 44, BIP 67, BIP 111, BIP 125, BIP 130
Precedence: list

On 24.08.2016 16:18, Jonas Schnelli via bitcoin-dev wrote:
> 
> Another thing that I think could be a BIP misdesign:
> 
> BIP44 Gap Limits
> From the BIP:
> 
> ----------
>   "Address gap limit is currently set to 20. If the software hits 20
> unused addresses in a row, it expects there are no used addresses beyond
> this point and stops searching the address chain."
> ----------
> 
> * Does that mean, we do a transaction rescan back to the genesis block
> for every 20 addresses?

As I understand it, you can scan sequentially starting with the genesis
block (or with a block at around the time when BIP44 was written).  Then
if you find a new transaction, which requires to generate new addresses,
you generate them and scan further from that point on.  This way you can
scan in a single pass if the scanning process calls you back when it
finds a transaction and allows you to change the set of addresses on the
fly.

  Jochen