I’ve been digging into bitcoin and came across some stuff that’s kinda confusing. I read about how miners can replace blockchain blocks if they have enough power, which is called a 51% attack. Is that right? It sounds like it means rewriting transaction history, which seems super tough.
So far, no one has pulled off this type of attack. It’s not impossible, but honestly, the odds are slim. Even trying it comes with huge risks, and getting the required 51% power is a massive investment. And if a bunch of pools teamed up, it would be obvious, and they’d take a hit on their reputation.
I found some articles mentioning GHash.io almost hitting 51% back in the day. The community quickly reacted and shifted away, balancing the hashrate. Plus, they capped their power at 40% to avoid issues. But yeah, outside of Bitcoin, other coins have seen 51% attacks. For Bitcoin, the cost to attempt this is just too high now.
Cex.io had 52% at one point, but it wasn’t a big deal since they mined honestly. They adjusted their numbers to stay below 50%. If a pool has 60% but mines straight, it doesn't matter. Miners can always switch pools. What’s scary is if one company had 60% of all hardware and was mining dishonestly.
Yeah, it can happen, but it's super costly. You’d need control over like 1100 eh to match the current network power, which is tricky. Maybe you'd need 1400 eh to be safe.
The issue is more centralization. If one pool gets too much power, people might flock to them 'cause they seem honest. But 51% isn’t necessarily an attack; it’s just the threshold to start one.
If multiple pools are running, like at least 4 or 5, it’s easy to redistribute power from one to others. More pools would be cooler, but they cost money to operate, and there are really only a handful of big players.
I’m not a mining expert, but I know pools combine resources. So if you have 60%, your chances of solving the block puzzle go up. And if they’re not shady, other miners might want in on the action.
Totally agree with what you said. GHash.io hit over 50% in 2014 but failed to exploit it because other pools stepped up. Histories show no other pool has come close since then. So, yeah, it's tough to pull off a 51% attack.
It's about having enough hashrate to make the double-spend attack work. There’s a calculator that shows your chances based on hashrate and block depth. Mining pools probably don’t wanna risk their rep by misusing their hashrate.
Altcoins have suffered 51% attacks before, some died off, some survived. There was this one case back in 2012 with CoiledCoin that a lot of people think was orchestrated.
Theoretically, a 51% attack is doable, but it doesn’t give total control over the blockchain. The attacker can’t just steal bitcoin at will. They can cancel their own transactions, like double-spending, but that costs a lot.
Honestly, I think it’s a myth. This whole concern gets tossed around by people who push for POS. You can realistically pull off a 51% attack in POS because it’s abstract. In POW like Bitcoin, it’s more of a self-destructive move.
I'm unsure about what happened with Monero last August. Some say it had a 51% attack, but details vary. Claims are all over the place about how many blocks were orphaned, and I haven't followed it closely.
A small attack could have been possible, but remember having 51% hashrate doesn’t mean an attack happened. For a successful attack, they’d need to double-spend at least once. Orphan blocks can happen for other reasons too.
Satoshi once said, as long as honest nodes control more CPU power than attackers, the system is secure. An attacker would be better off playing by the rules than undermining everything.
Right! It’s way smarter to mine honestly than to break the system. If you have that much power, you’d be better off using it to find more blocks than to threaten the network.
Just so you know, the 51% attack on Monero is probably FUD. BitMEX noted the hashrate was actually lower than claimed. And as I said, re-orgs can happen with less than 51% hashrate, but success isn’t guaranteed.
Seems like both sides of the story have their reasons to spin the truth. I ignored all the noise while it was happening. Pro-Monero folks wanted to protect their investments, while the haters wanted to exaggerate the attacks.