Writer’s observe: In my opinion BIP110 is each ineffective and dangerous, and I do anticipate it to fail (see situation 1). Regardless of this I attempted to jot down this text as factually as I may, entertaining completely different attainable eventualities, as I do hope it might present some readability on this smooth fork try.
The OP_RETURN debate has escalated to the purpose the place Bitcoin Knots carried out BIP110: a consensus protocol change that quickly limits the dimensions of OP_RETURNs and intends to cut back different sorts of knowledge on Bitcoin’s blockchain as nicely.
Nonetheless BIP110 doesn’t have consensus: not everybody agrees there’s an issue that requires fixing within the first place, nor that BIP110 solves it in any significant method, whereas it restricts Bitcoin in probably dangerous methods. Most clearly, Bitcoin Core — nonetheless by far the most-used Bitcoin implementation — has not adopted BIP110, whereas just some 1-2% of hash energy has been signaling assist for it in current weeks.
However, BIP110-nodes like Bitcoin Knots will quickly — ranging from block 961,632, to be mined on or round August 8 — reject blocks that don’t sign assist for the improve.
Listed below are the three fundamental eventualities for a way that might play out.
Situation 1: (virtually) no miners sign
If present miner signaling is any indication, that is the situation to anticipate.
From the angle of anybody working Bitcoin Core or different non-BIP110 implementing nodes and wallets (the overwhelming majority of the Bitcoin ecosystem) blocks will likely be mined as typical, and transactions will likely be processed like regular too. Anybody who’s not actively monitoring these occasions on social media or elsewhere could not even bear in mind that something uncommon is occurring, and in a sensible sense for them there actually gained’t be; BIP110 doesn’t have an effect on them.
The identical just isn’t true for anybody working Bitcoin Knots or different BIP110-enforcing nodes, nonetheless. Since their software program will reject non-signaling blocks, they principally wouldn’t see any new blocks in any respect (or maybe a couple of per week), and incoming and outgoing transactions gained’t verify (or extremely gradual). In sensible phrases, these nodes would stall and turn into unusable.
If this occurs, BIP110 proponents should determine between ready to see if issues enhance for them (see situation 3), giving up (switching again to non-BIP110 software program), or deploying a subsequent protocol change, like arduous forking to a special proof-of-work mining algorithm.
Such a tough fork might enable for mining with GPUs once more, due to this fact letting extra folks mine new blocks to generate a blockchain with the BIP110 guidelines enforced. Nonetheless this may additionally imply that BIP110/arduous fork nodes completely cut up off from the remainder of the Bitcoin ecosystem to basically create a brand new cryptocurrency. (Extra on this under)

Situation 2: (virtually) all miners sign
That is the situation a number of distinguished BIP110 proponents predict.
On this situation, when the necessary signaling window begins, all miners will immediately sign for BIP110. Or a minimum of, a majority of miners will sign AND reject any non-signaling blocks, so that every one blocks that find yourself within the blockchain embrace a BIP110 sign.
If this occurs, all Bitcoin nodes (Knots and Core alike) stay appropriate, and the indicators within the blocks point out that miners plan to start out implementing the BIP110 guidelines one other two weeks later. BIP110-violating transactions ought to by early September now not find yourself in blocks.
In essence, that is the success situation for BIP110; though solely a small faction of builders, miners and customers pushed for it, the improve goes into impact throughout your entire community.
…Nonetheless even on this situation there is a crucial caveat.
Blockchain signaling is a helpful coordination mechanism for smooth fork deployment, nevertheless it technically doesn’t assure that the brand new guidelines will likely be enforced. Miners can sign assist for the improve with out truly utilizing BIP110 software program, which they for instance may elect to do merely to make sure their blocks aren’t rejected by Bitcoin Knots nodes in the course of the necessary signaling window.
Bitcoin’s protocol guidelines are in the end enforced by financial nodes nonetheless, and nothing presently signifies that almost all of those will implement the BIP110 guidelines even when all blocks embrace a sign. So if BIP110-violating transactions are later accepted by most miners regardless, these financial nodes would settle for blocks that embrace them, whereas BIP110 nodes wouldn’t. The blockchain would cut up between nodes that do and don’t implement BIP110 in spite of everything.

Situation 3: a large minority of miners sign
That is the situation that will instantly cut up the chain.
Presently some two p.c of miners sign assist for BIP110, which might be too little to be significant (see situation 1). However let’s think about this shortly will increase tenfold or so. We additionally should think about that this sizable minority itself rejects any non-signaling blocks— else it might nonetheless be indistinguishable from situation 1 the place BIP110 nodes stall (since they require ALL blocks to incorporate a sign).
If the sizable minority is each signaling and rejecting non-signaling blocks, they’d begin to construct their very own minority blockchain with solely signaling blocks in it. Blocks on this minority chain would verify considerably slower than typical — perhaps only one or two per hour — however BIP110 nodes stay fairly usable. And after a couple of months the mining problem would regulate, so blocks are discovered (nearer to) six occasions per hour once more. One other couple of weeks later the BIP110 guidelines would go into impact.
In the meantime, Bitcoin Core and different non-BIP110 implementing nodes would nonetheless function pretty usually as nicely. Their blocks will verify a bit bit slower for some time — perhaps about 4 or 5 per hour — however after a pair weeks mining problem adjusts right here too, to additionally carry this again to 6 per hour on common. The BIP110 guidelines would by no means go into impact on this blockchain.
Because of this, a BIP110 blockchain and a blockchain with the unique guidelines would then exist facet by facet as two completely different cryptocurrencies, indefinitely.
There’s one notable caveat to this situation as nicely, nonetheless. If the BIP110 chain have been to overhaul the unique chain in size afterward (on account of miners transferring to the BIP110 chain), all nodes — Core and Knots alike — would settle for the BIP110 chain as the one chain. The unique chain would on this case be discarded, or worn out.
This one-sided wipe out threat is in truth why BIP110 proponents anticipate all miners to sign preemptively, stopping a cut up. Miners gained’t wish to mine on a blockchain that may later be discarded, they argue, as that will additionally imply dropping all block rewards they earned on it.
Really, customers and miners that wish to stop that the unique chain can get worn out may achieve this nonetheless: they’ll manually invalidate any block on the minority BIP110 chain whereas it nonetheless is the minority chain. This manner their nodes would reject switching to it even when it turns into longer at any level sooner or later, making the cut up everlasting additionally.

So what precisely occurs if the chain completely splits?
If and when the Bitcoin blockchain completely splits, it basically marks the creation of a brand new cryptocurrency, or forkcoin. Everybody who owns BTC on the time of the cut up routinely receives the equal quantity of cash on the brand new blockchain, not not like what occurred with Bitcoin and Bitcoin Money in 2017.
Nonetheless in actuality this stuff aren’t essentially as simple, and if BIP110 does trigger a series cut up underneath any of the eventualities above there’ll doubtless be some issues.
For one, there’ll virtually actually be disagreement over which facet of the chain represents “Bitcoin” (“BTC”), and which facet is the brand new forkcoin. It appears doubtless nonetheless that the blockchain with the unique guidelines will by most individuals be thought-about “Bitcoin”, whereas the blockchain with the BIP110 guidelines will likely be known as one thing else; we’ll name it “BIP110 coin” for now.
Accessing the BIP110 cash then, would require BIP110-specific software program like, certainly, Bitcoin Knots. The brand new cash gained’t present up on Bitcoin Core nodes or most wallets.
Nonetheless, BIP110 doesn’t presently embrace replay safety. Because of this transactions on one chain may be copied (“replayed”) on the opposite chain. As an alternative of simply sending BTC, customers may unknowingly additionally ship the equal BIP110 coin to an equivalent tackle on the BIP110 chain— or vice versa.
It’s tough to estimate at this level how a lot the forkcoins will likely be value, or even when they are going to be value something in any respect. The shortage of curiosity in shopping for BIP110 cash through fork future contracts does counsel there might not be a lot curiosity to purchase them after a cut up both. However in case you nonetheless wish to ensure you’ll obtain BIP110 cash if there are any, it’s most likely greatest to self-custody your BTC (have entry to your personal keys), and don’t ship any transactions till the mud settles and there may be extra readability on how you can proceed.
Aaron van Wirdum is the previous Editor-in-Chief of Bitcoin Journal and writer of The Genesis Guide: The Story of the Folks and Tasks That Impressed Bitcoin. Observe him on Nostr.
