bitcoindevkit
Update `bdk_electrum` to use electrum's merkle proof API
Describe the enhancement
As mentioned by @LLFourn in https://github.com/bitcoindevkit/bdk/pull/976#discussion_r1193920143:
... I think electrum really intends for you to use the merkle proof API. Best solution is to do that and attach confirmation time of each block to
LocalChain.
Additional context
- This should be attempted after #976 is merged.
~* This may require changing
LocalChain.~
After discussion with @evanlinjin, it has been decided that I will attempt to pick this up.
We've started a rough document here of the plan: https://hackmd.io/@bdk/electrum_spv
FYI, since I needed it for LDK's electrum integration, I added a utility to validate merkle proofs to rust-electrum-client a while back: https://github.com/bitcoindevkit/rust-electrum-client/pull/122
Just mentioning it as they could potentially be useful.
Just chiming in that I think this should be a priority. It will need very careful engineering to make efficient. I think perhaps we should have CheckPoint in the BdkElectrumClient to keep track of re-orgs. This would allow us to cache merkle proofs and block headers (because we know they haven't changed). Despite this I predict the code would actually get simpler. No more weird loop and restarting in case of re-orgs.
To start off with we don't need to actually return the proofs. They can just be used to make our algorithm actually sound and robust.
Since this doesn't touch the wallet APIs I moved it to the beta milestone.
@notmandatory my suggestions on #1489 means it would touch the wallet API. Please take a look.