Bitcoin's mining difficulty has increased by 41.9% over the last 30 days • Hacker News Board

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#131

Post by gcr » Tue, Dec 22, 2015, 4:25 AM UTC

cgjaro wrote: post #99

sanswork wrote: post #56

Earlier quoted context omitted.

So less than half of one datacentre entirely owned by one company is enough to commit a 51% attack. I get that they say they are going to work on distribution these chips to ensure they don't end up in that position but let's be honest they just destroyed any claim that the network is powerful enough to avoid malicious control by one miner now. They've not even raised that much money.

This DC cost $100 million. Not exactly pocket change. http://www.coindesk.com/bitfury-details-100-million-georgia-... Plus, with BitFury online, the cost of a 51% attack just raised to $200 million. The only reason it is (currently, for a short time) hypothetically possible to 51%-attack the network with a budget in the low hundreds of million of dollars is because most of the miners are not using such efficient 16 n…

Yeah, but how many bitcoins is USD$ 100 million worth?

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#132

Post by woah » Tue, Dec 22, 2015, 4:26 AM UTC

jnbiche wrote: post #41

woah wrote: post #33

Earlier quoted context omitted.

Not 100% sure, but from your tone it sounds like you think they are performing some kind of service. This is not true. Miners do not increase the number of transactions the network can handle. An infinitesimal amount of the electricity going into mining is actually goes to process transactions. A raspberry pi in a shoebox running mySql is capable of processing more transactions than the entire bitcoin network, liquid…

> All that mining does is give the person with the most hashrate more voting power in which transactions will be accepted. Innovation in mining hardware and data centers does not in any way increase bitcoin's security. This is completely wrong. The higher the difficulty, the harder it becomes to attack the network, which is a critical feature. If anyone who rented a data center could attack Bitcoin at this point, it…

No. Read what I said. "Innovation in mining hardware and data centers does not in any way increase bitcoin's security."

If everyone can use technology to push a higher hashrate, then what has changed? The people who can get their hands on new mining chips first have an advantage for a little while, but in the end it's a zero-sum game. The pie is 100% of hashing power/block validation power. How can you divide a pie into more than 100%?

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#133

Post by woah » Tue, Dec 22, 2015, 4:27 AM UTC

feral wrote: post #37

woah wrote: post #33

Earlier quoted context omitted.

Not 100% sure, but from your tone it sounds like you think they are performing some kind of service. This is not true. Miners do not increase the number of transactions the network can handle. An infinitesimal amount of the electricity going into mining is actually goes to process transactions. A raspberry pi in a shoebox running mySql is capable of processing more transactions than the entire bitcoin network, liquid…

>Innovation in mining hardware and data centers does not in any way increase bitcoin's security. Not sure exactly what you mean here - mining, and mining faster, generally increases the computational resources another third party would need to 51% attack the network.

If there are faster mining chips available, is not easier the third party to hash as well?

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#134

Post by woah » Tue, Dec 22, 2015, 4:28 AM UTC

CyberDildonics wrote: post #85

woah wrote: post #33

Earlier quoted context omitted.

Not 100% sure, but from your tone it sounds like you think they are performing some kind of service. This is not true. Miners do not increase the number of transactions the network can handle. An infinitesimal amount of the electricity going into mining is actually goes to process transactions. A raspberry pi in a shoebox running mySql is capable of processing more transactions than the entire bitcoin network, liquid…

It does specifically because it increases the barrier to entry. This means the likelyhood of an attack is lower and the cost of an attack is higher. If your Rasberry PI ledger had a market cap of multiple billions of dollars, the likelyhood of an attack that would either steal people's money or shut it down would be pretty much %100.

increases the barrier to entry === centralization

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#135

Post by ozmbie » Tue, Dec 22, 2015, 4:28 AM UTC

geofft wrote: post #103

sowbug wrote: post #82

Earlier quoted context omitted.

Malice isn't enough. The only special power of a 50% miner is to consistently resolve double-spend attempts in its favor. If this happened, it would surely lower the value of Bitcoin. This, an attacker must be not just malicious but also irrational enough to forfeit the $800,000 in Bitcoin that it creates daily by virtue of its 50% control of the network. (6 blocks/hour x 24 hours/day x 25 bitcoin/block x $450/bitcoi…

Stupid question: if control of 50% of the hash power is so unimportant, why does Bitcoin rely on hash power anyway? Why not simply have a consensus system without proof-of-anything?

If you remove proof-of-work, then the question then becomes: what else do you measure consensus by? A few other crypto currencies have tried other metrics but they all aim to for the same thing: removing the need for human trust.

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#136

Post by HappyTypist » Tue, Dec 22, 2015, 4:29 AM UTC

The billion dollar question is how we can have completely decentralised (and not merely distributed) consensus without proof of work. It's a difficult question, and various proposals like Proof of Stake (not secure) and Consensus Ledger (not secure, not decentralised) have all failed technically and on the market.

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#137

Post by iofj » Tue, Dec 22, 2015, 4:33 AM UTC

sowbug wrote: post #82

sanswork wrote: post #56

Earlier quoted context omitted.

So less than half of one datacentre entirely owned by one company is enough to commit a 51% attack. I get that they say they are going to work on distribution these chips to ensure they don't end up in that position but let's be honest they just destroyed any claim that the network is powerful enough to avoid malicious control by one miner now. They've not even raised that much money.

Malice isn't enough. The only special power of a 50% miner is to consistently resolve double-spend attempts in its favor. If this happened, it would surely lower the value of Bitcoin. This, an attacker must be not just malicious but also irrational enough to forfeit the $800,000 in Bitcoin that it creates daily by virtue of its 50% control of the network. (6 blocks/hour x 24 hours/day x 25 bitcoin/block x $450/bitcoi…

Not true. A malicious 50% miner can cancel any transaction it wants, not just fix doublespend. Assuming the transaction was sufficiently recent (the more hash power they have the more such a transaction can be in the past).

So they can "unspend" their own bitcoins, as follows : use 51% of your hash power to create a parallel blockchain, which is not published. Include all transactions, except the one you used to buy a TV. Put something else in it's place. Keep doing this until the TV is shipped/arrived. Then publish the parallel blockchain. Boom. Unspent.

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#138

Post by karlkatzke » Tue, Dec 22, 2015, 4:36 AM UTC

rockyleal wrote: post #121

douche wrote: post #108

Earlier quoted context omitted.

You'd think Canada would have more major data centers. They've got a lot of extremely cheap hydro power. You could surely lay ultra-high-speed fiber along the same right-of-ways that the transmission lines use. Also, it's cold as hell more often than not, so cooling is less of an issue than putting them out in the desert somewhere.

Bitcoin miner's dilemma: Should I mine where it's hot for the free solar energy or should I mine where it's cold for the extra refrigeration?

Photovoltaic power is actually less efficient where it's warmer. The ideal for photovoltaic generation is somewhere cold but sunny. And I'm not aware of too many solar thermal plants that are online and profitable versus other generating methods.

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#139

Post by ikeboy » Tue, Dec 22, 2015, 4:37 AM UTC

throwaway45872 wrote: post #109

mrb wrote: post #26

Nobody on HN pointed out who is behind the increase... This is BitFury who just launched a 40 megawatt data center filled up with their new 16 nm chips which reportedly achieve approximately 0.06 joule per gigahash. They also use immersion cooling which gives them an insane PUE of 1.02. So the mining capacity of this DC alone is ~650 Phash/s! We saw an increase of ~200 Phash/s in the last 30 days, so presumably they…

(Note: Since most HN readers are technical, this comment is being downvoted by bitcoin enthusiasts among them. You won't see many replies from them to this comment, since their reaciton is political and not a technical statement. Still, I'll keep it up. This comment is currently at -2.) To put this into context, by comparing it with a centralized version, an equivalent number of actual transactions could be done at a…

You're wrong. Even without any mining, running a full node requires 2GB of RAM. Even if you do less than a full node, you'll find it hard to fully process 100x transactions on less than 2GB.

Also, you don't seem to understand the point of PoW.

Re: Bitcoin's mining difficulty has increased by 41.9% over the last 30 days

#140

Post by ozmbie » Tue, Dec 22, 2015, 4:40 AM UTC

jnbiche wrote: post #41

woah wrote: post #33

Earlier quoted context omitted.

Not 100% sure, but from your tone it sounds like you think they are performing some kind of service. This is not true. Miners do not increase the number of transactions the network can handle. An infinitesimal amount of the electricity going into mining is actually goes to process transactions. A raspberry pi in a shoebox running mySql is capable of processing more transactions than the entire bitcoin network, liquid…

> All that mining does is give the person with the most hashrate more voting power in which transactions will be accepted. Innovation in mining hardware and data centers does not in any way increase bitcoin's security. This is completely wrong. The higher the difficulty, the harder it becomes to attack the network, which is a critical feature. If anyone who rented a data center could attack Bitcoin at this point, it…

That's circular logic thogh. If you built a data center capable of staging a 51% attack, you haven't made the network harder overall. You've already gained enough power to do an attack.

It might encourage others to compete, and the arms race continues. But if too much of the network is controlled by a minority, then it's not automatically more secure.