 First and highest voted question comes from Lee the Binance rollback that was proposed Binance said they considered rolling back the Bitcoin chain But then decided against it how on earth would that have even happened if they had decided to go that route What would have happened would just would this just mean Binance launching a 51% attack Yes, Lee so that's basically what they were proposing in order to roll back the chain what it would require On Binance's side would be to persuade enough miners 51% or more of the miners to go back Pick a block before the withdrawals happened That was spending Binance coins and sending them to an attacker address The withdrawals that were recorded on the blockchain pick a block before they happened Set that as the parent of the next block and start mining from that point Onwards now imagine that they decided to do this a day After the attack so at that point they would have to persuade miners to go back 145 blocks Which would be you know exactly one day or some such amount and start mining a hundred and forty-five blocks in the past and then use their hashing power to overtake the 49% of miners presumably that would be mining from the current block from the longest chain and overtake them and Therefore cause a reorganization of the chain and during this time what they would do is they would deliberately Mine a double spend transaction from Binance Spending all of the outputs that was stolen by the attacker to Binance addresses and once that's in there Then the transaction from the attacker would not succeed because Those coins will have already been spent on the chain being mined by the miners trying to do the rollback But think about it for a second like a fifty one percent is not actually enough and part of the reason It's not enough is because at a rate of one percent advantage over the chain being mined by the forty nine percent They would only achieve a one block gain Every day so every hundred blocks they catch up by one Block now think about this for a second the attacker is the the chain that the miners are trying with a fifty one percent to Remind to reorganize Only has a one percent advantage over the one being mined by the rest of the miners at forty nine percent But it starts more than a hundred and forty five blocks in the past. Let's say that Binance Didn't manage to launch this attack for a day at this point Gaining only one percent per day means only one block in a hundred So as they mine block minus one forty five the other forty nine percent of the miners mine block one Extending their chain by one just about ten percent faster. So after they've mined a hundred blocks There's still forty five behind but the other chain has now mined 99 blocks also and so they started a hundred and forty five blocks behind and A hundred blocks later. They're a hundred and forty four blocks behind Another hundred blocks. They're a hundred and forty three blocks behind At that rate it would take them a Hundred and fifty days almost to catch up overtaken rewrite The chain that is a very very long time during which if anything goes wrong Let's say just one percent of the miners abandon this effort and go to the other side. It's all over all of that Energy that they tried to put towards reminding the chain rolling it back is wasted Now let's say that Binance managed to do this in a much shorter period of time They acted very very quickly collaborated with the miners don't know how they would do that exactly They'd have to figure out Perhaps by persuading pools to join them But the pools may start losing miners is a very very contentious act and they did it within five blocks Well, even in that case it would still take a very very significant effort to overtake the other chain because they're still only 10 sorry 1% faster they'd have to get an overwhelming number of miners on their side And they'd have to do it very very quickly for this to even Be doable From a pure hashing perspective As some people have suggested that one of the ways Binance might get miners to do this Would be to bribe them and of course one way to bribe them is to make sure that the transaction that they introduce which Spends Binance's outputs back to Binance carries very very high fees and therefore the miners are Incentive they're gonna get paid off for this and those fees would have to be more than the rewards of The blocks that the miners would be rolling back So let's say they they they rolled back five blocks. Well the fees they would have to pay to bribe the miners would have to be more than 60 Bitcoin because you see the miners can make 12 and a half Bitcoin Just by continuing to mine blocks on the normal chain if they go back and try to roll back the chain That energy is going to be wasted even if they win Presumably the 51% of miners who took this chance have already Mined those blocks or participated the mining of the blocks. They've already received the reward They go back and spend the energy twice They're not receiving two rewards because either one or the other chain is gonna succeed They're only gonna get paid once Which means as a result that Binance would have to bribe them by the entire reward amount of however many blocks they're trying to overwrite and Then some because they're doing something very risky very very risky because if it fails That's energy loss Then they're not gonna get the reward from Binance because they don't mind the transaction that has the fees and Then the is another little wrinkle because at any point in time the attacker can add a brine of Their own and the only way the easy way to do that is simply to chain a transaction on top of the stolen funds That also pays a big fee to the miners But here's the trick the bribe from the attacker is much less risky because all the miners have to do is not play The rollback game and just continue to mine the chain Which is a much less risky proposition because they're not spending any energy to go against consensus and they'd be able to earn that reward with almost 100% certainty and so at that moment in time if they roll back the chain they lose the attackers bribe But that's very risky But if they don't roll back the chain they get the attackers bribe for much less risk Which means the attacker doesn't have to bribe them more than the block reward because they're not wasting energy and Doesn't have to bribe them more than Binance in fact has to bribe them a lot Lot less because it's a much less risky proposition So the bottom line here is how would the proposed rollback work? It wouldn't it's as simple as that it wouldn't it's too risky. It would take enormous coordination it would have to be done immediately and There's no way in my mind that Binance would be able to incentivize enough miners once the miners understood that This could easily be thwarted by a simple bribe by the attacker that would cause them to waste all of that energy It's not as easy as people think to attack the chain Even when you have motivation and hundreds of millions of dollars at stake