An apparently harmless bug has been exploited in Bitcoin Cash on or around the same time as the currency upgrades to implement Schnorr Signatures.
Some are saying this is a bug from the fork itself, while some are saying it is an old or legacy bug from the Bitcoin Core codebase that was exploited at the same time as the fork.
The problem appears to be a failure to update the old code to account for OP_CHECKDATASIG and OP_CHECKDATASIGVERIFY transactions, two features by Peter Todd if memory is not mistaken. A transaction containing these two operations, therefore, is wrongly considered as invalid.
All funds seem to be very safe. The greatest damage here appears to be just that a transaction is not included in a block with recent blocks containing very few or no transactions.
It appears this is now sort of getting back to normal. Devs have seemingly identified the bug. A fix has already gone out or is in the process of doing so.
This is a developing story, so full details are not clear, but it appears to be mainly a legacy bug.
What gain in exploiting it is unknown. It looks like none as far as monetary aspects are concerned. Its revelation however is obviously helpful.
It might have been more helpful if it were done in a proper way, but maybe they’re a bit shy and perhaps feel it might have been a bit complicated to do it in the proper way.
Their reasons for exploiting it likely have two possibilities. The first might be that they perhaps want to make BCH devs look a bit incompetent, which would be far too stupid because who is without bugs to throw code.
The more likely reason thus, or at least what we’d like the reason to be, is that they want to see the Schnorr Signatures in action and therefore are sort of strengthening the code.
Competitive cooperation is what this should be called. Smart kids that pretend to hate each other while they’re really in love.
The first Schnorr transaction has apparently already been performed in BCH. Bitcoin is trying to make theirs look even more cool by calling it Taproots.
Ping pong through code as the fight goes on for the best money network with any bug at the protocol level more of an interesting artifact for coders as here funds are safu.