David A. Harding [ARCHIVE] on Nostr: 📅 Original date posted:2020-04-22 📝 Original message: On Mon, Apr 20, 2020 at ...
📅 Original date posted:2020-04-22
📝 Original message:
On Mon, Apr 20, 2020 at 10:43:14PM -0400, Matt Corallo via Lightning-dev wrote:
> A lightning counterparty (C, who received the HTLC from B, who
> received it from A) today could, if B broadcasts the commitment
> transaction, spend an HTLC using the preimage with a low-fee,
> RBF-disabled transaction. After a few blocks, A could claim the HTLC
> from B via the timeout mechanism, and then after a few days, C could
> get the HTLC-claiming transaction mined via some out-of-band agreement
> with a small miner. This leaves B short the HTLC value.
IIUC, the main problem is honest Bob will broadcast a transaction
without realizing it conflicts with a pinned transaction that's already
in most node's mempools. If Bob knew about the pinned transaction and
could get a copy of it, he'd be fine.
In that case, would it be worth re-implementing something like a BIP61
reject message but with an extension that returns the txids of any
conflicts? For example, when Bob connects to a bunch of Bitcoin nodes
and sends his conflicting transaction, the nodes would reply with
something like "rejected: code 123: conflicts with txid 0123...cdef".
Bob could then reply with a a getdata('tx', '0123...cdef') to get the
pinned transaction, parse out its preimage, and resolve the HTLC.
This approach isn't perfect (if it even makes sense at all---I could be
misunderstanding the problem) because one of the problems that caused
BIP61 to be disabled in Bitcoin Core was its unreliability, but I think
if Bob had at least one honest peer that had the pinned transaction in
its mempool and which implemented reject-with-conflicting-txid, Bob
might be ok.
-Dave
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20200422/aa4c89f0/attachment.sig>;
📝 Original message:
On Mon, Apr 20, 2020 at 10:43:14PM -0400, Matt Corallo via Lightning-dev wrote:
> A lightning counterparty (C, who received the HTLC from B, who
> received it from A) today could, if B broadcasts the commitment
> transaction, spend an HTLC using the preimage with a low-fee,
> RBF-disabled transaction. After a few blocks, A could claim the HTLC
> from B via the timeout mechanism, and then after a few days, C could
> get the HTLC-claiming transaction mined via some out-of-band agreement
> with a small miner. This leaves B short the HTLC value.
IIUC, the main problem is honest Bob will broadcast a transaction
without realizing it conflicts with a pinned transaction that's already
in most node's mempools. If Bob knew about the pinned transaction and
could get a copy of it, he'd be fine.
In that case, would it be worth re-implementing something like a BIP61
reject message but with an extension that returns the txids of any
conflicts? For example, when Bob connects to a bunch of Bitcoin nodes
and sends his conflicting transaction, the nodes would reply with
something like "rejected: code 123: conflicts with txid 0123...cdef".
Bob could then reply with a a getdata('tx', '0123...cdef') to get the
pinned transaction, parse out its preimage, and resolve the HTLC.
This approach isn't perfect (if it even makes sense at all---I could be
misunderstanding the problem) because one of the problems that caused
BIP61 to be disabled in Bitcoin Core was its unreliability, but I think
if Bob had at least one honest peer that had the pinned transaction in
its mempool and which implemented reject-with-conflicting-txid, Bob
might be ok.
-Dave
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20200422/aa4c89f0/attachment.sig>;