From: Luke Dashjr <luke@dashjr.org>
To: bitcoin-dev@lists.linuxfoundation.org,
	Andreas Schildbach <andreas@schildbach.de>
Date: Fri, 13 Apr 2018 22:52:23 +0000
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Message-Id: <201804132252.24419.luke@dashjr.org>
Subject: Re: [bitcoin-dev] BloomFilter issue with segwit addresses
Precedence: list

As I understand it, the plan is to deprecated and remove BIP37 entirely once 
BIP158 is implemented and deployed.

In the meantime, Bitcoin Knots supports the MSG_FILTERED_WITNESS_BLOCK 
extension to download witness data. (Note that light clients currently have no 
way to verify the witness data is correct.)

As far as matching goes, why not look for the specific COutPoints? That should 
work already with standard BIP37.

Luke


On Friday 13 April 2018 3:32:15 PM Andreas Schildbach via bitcoin-dev wrote:
> Anton, a developer on the bitcoinj maiing list, recently made me aware
> [1] of a compatibility issue between segwit and BIP37 (Bloom Filtering).
> 
> The issue affects only P2WPKH and the special case of transactions
> without change outputs (such as when emptying a wallet). In this case,
> neither inputs not outputs contain any data elements that would cause a
> match for the filter. The public key, which would match, goes to the
> witness but not to the input.
> 
> My suggestion was to include an OP_RETURN output with a matching public
> key in such transactions. Anton confirmed that this workaround is indeed
> working. But of course it nullifies some of the segwit's size improvements.
> 
> I wonder if Bitcoin Core would be willing to extend the BIP37 matching
> rules such that data elements in the witness are also matched against?
> 
> 
> [1] https://groups.google.com/d/msg/bitcoinj/SJpLgjowc1I/V7u2BavvAwAJ
> 
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