Laugh, it's better for your health.

Do I also get to use the "it only goes against your morals" card when people talk about how government is evil, or for that matter, how stealing, enslaving, kidnapping, raping and murdering are (or are these ok too)?

Aren't we missing a few things?

1. Some things are inherently immoral, like eating humans, having sexual intercourse with a sibling/parent, and using drugs.

2. I never understood why libertarians, who think "liberty", whatever that means, is some sort of ultimate moral principle, support the manipulation of people into surrendering their liberty and free will to drug addiction (or, in the case of hallucinogenics, to a state of detachment from reality).

3. Using drugs is not a victimless crime. This is especially pronounced with cigarettes - Some people think they have the right to smoke wherever they want and subject their surroundings to noxious, foul-smelling gases. Even laws restricting places allowed for smoking have so far proven ineffective against this. At one time I had the displeasure to work with someone who smoked marijuana, when he came back from a smoking session he smelled so bad my eyes watered. What about my liberty to enjoy clean air?

So, for these reasons, as well as the obvious negative consequences for the success of Bitcoin, drug dealers should not be advertised in any official site.

I hear you . Not yet ready to ditch mine, though.

The first step is to either install the Bitcoin software or create a MyBitcoin account.
If there's some level of trust in your gaming community, all you need is to post your Bitcoin address on your site and tell people to send you a message how much they donated.
If you need to be able to verify who paid what, you need to hand out a different address to each payer. There are some existing solutions for automating this.
I don't know if a platform like Amazon or iTunes will allow you to accept Bitcoin payments.

Hi Robert,

You have misunderstood some things about how Bitcoin works (not your fault, the current explanations are terrible).

1. There will never be more than 21 Million bitcoins. The difficulty of creating bitcoins is dynamically updated based on the total computing power of the network. At this point in time 7000 bitcoins are generated per day, and if someone decided to buy all the computers in the world and use them to generate bitcoins, there will still be 7000 bitcoins generated per day. Generation per day is set to decrease on a known schedule so there will never be more than 21M.

2. Creating Bitcoin blocks does requires energy, yes. Printing banknotes and shipping them internationally, and running servers for Visa, PayPal, banks etc. also requires energy, perhaps much more. The energy spent is more than outweighed by the benefits.

3. You can use government-issued money, yes. But Bitcoin has an endless list of advantages. Off the top of my head: Every person can store their own wealth securely, they can transfer money internationally easily, quickly and cheaply (unlike wire transfers that require $50 fees, filling forms and waiting a few days, or CC/PP which require 3% fees), transactions cannot be reversed (a major issue for people who accept PP), there is no single point of failure, it's an international currency which gives it more stability.

4. You can buy various things with bitcoins, and the list keeps expanding. You can even buy food, although indirectly (there are vendors who will sell you gift cards to restaurants and retails shops for bitcoins).

I don't expect you to hop on the Bitcoin bandwagon, but do know that Bitcoin isn't going anywhere.

Right, but what the miners are calculating are real hashes that will later be recognized by the network. If a pool decided to implement their own scheme the resulting blocks will not be accepted by the network. If, with the current protocol, there is some way for pool miners to work on something other than the final hash while still knowing if their hash is a share, it means the hashing function is broken.

Focus your energies on implementing exploits that are possible .

That was tongue-in-cheek, but I do think it's beneficial for Bitcoin (and pooled mining in particular) if people develop proof-of-concept exploits of suspected vulnerabilities, of course while being open about their intentions.

For this to work you need all persuaders to have been a customer for a while and have made a significant amount of purchases, otherwise it's just spam. Because Bitcoin is still small, it may be hard to find enough such people for any entity. We can't win with numbers, we can only win with ideas and for that one person suffices.

But by all means, if there are more last.fm customers here please do write to them.

Fair enough. Figuring out if there are downsides to oblivious shares was the purpose of this thread, but I don't really believe they are any.

"Oblivious shares" means that a participant can't know if his shares are winning. I think what you're really asking is if my suggested protocol change achieves oblivious shares. And I say yes, because in the notation of my outline, the attacker doesn't know A which is required to find C which needs to be valid. He only knows B which is a public commitment to a specific value A. Only the operator knows A and can use it to assemble a valid block, when given the right share.

Of course. If he's invested in 20+ computers, he can invest in coding the automation.

Good point, though there will be false positives.
My main point is that if you make the protocol immune to such attacks, the operator doesn't need to deal with such nonsense and the participants don't risk being hurt by the countermeasures.

If I'm a prophet, sure.

But if I don't know if BTC price will rise or fall, and only know that a fall in BTC price will cause difficulty rise to slow down, so difficulty divided by price will not change much, and that at current difficulty/price buying a dedicated mining rig is insanely profitable... I choose the rig. (Plus it's satisfying and a positive externality).

I've been hearing about how mining was about to become unprofitable ever since I joined Bitcoin, but so far it didn't happen.

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He only needs to do an extra hash if the first hash solves difficulty 1, which happens once in 4 billion hashes. The extra work is negligible.

Bitcoin cares about the hash found by the miner, which needs to satisfy difficulty requirement. Unless the hashing function used is broken, if the miner doesn't know if he has a winning share then he doesn't know if he has a share at all, so he won't know to submit it to the pool.

Of course there will be more than 2 pools. I expect there to be at least one pool in every country.

You don't do it eternally. If you're holding a winning share, every share you submit is much more valuable than normal shares. Every unit of time you hold out you submit X additional valuable shares, but risk that someone will find a block and make all your shares lose their extra value. You submit the winning shares when the constantly increasing risk outweighs the reward. The greater your hashing rate the more effective the attack.

Of course you'll modify your miner rather than sitting at your computer. I don't understand what you mean by "troll the pool".

The attack can be used against proportional pools too, albeit less effectively. Why would a mining rig need to be reset? It just needs to switch to a different pool which I think takes about a second.

Compared to not doing this cheat, you only risk losing the reward for the single winning share, which is negligible. All the other shares you submit in the ambush are rewarded normally.

Who's "his"? The cheater can create several accounts and use an anonymization service to hide his IP.


Personally I don't understand why anyone would settle for "this attack will probably not be very effective and can be monitored" when they can easily have "this attack is impossible and you never have to worry about it again". However, since the answer to the title question is apparently "no", I won't pursue this further for now.

Demurrage is equivalent to simply increasing the block reward by the same percentage each year. I don't feel strongly about this either way, but I think that since we can't divine what the future growth rate of the economy will be, it's better to make the currency non-inflative rather than setting an arbitrary inflation rate.

I'm ok with receiving any amount from 0 to 21M. Whatever amount you choose to pay me, you can send it to the address in my signature.

It's the other way around. You take all of your miners off other pools and into this pool. After you've generated a hefty amount of shares for this pool, you submit the winning share and get a nice reward for all these shares.

The only sustainable way Bitcoin can live up to its role of being decentralized is if >50% of mining capacity is in the hands of small miners, and pools are what allows this to happen. That's far from petty.

You could just as easily take any problem solved by some part of the protocol and say "That's just a problem for X, you shouldn't change the protocol because of this."

I see that people prefer to discuss here whether fixing this is worth a protocol change, despite me clarifying that's not what the thread is about. So to make it less abstract I'll just outline my planned change (which of course could be improved by people experienced with the protocol):

1. The block header will include 3 extra fields, which for now I'll call simply A, B and C.
2. B is a hash of A.
3. The block hash will be a hash of all the usual stuff and also B.
4. C is a hash of the concatenation of the block hash and A.
5. For the block to be valid: Instead of requiring that the block hash is less than (1 / (2^32 * difficulty)), it is required that the block
hash is less than (1 / 2^32) and C is less than (1 / difficulty).
So solo miners choose anything for A (maybe all zeros) and hash it once to find B. Then they calculate hashes normally but with B added. When they find a difficulty-1 hash they calculate C to check if it satisfies the real difficulty.
For pools, the operators choose A randomly and keep it secret, but hand out B as part of the getwork. The participants can calculate the block hash and if it satisfies difficulty-1 they submit it as a share, but they don't know if it satisfies real difficulty because they don't know A and thus can't calculate C. The operator can of course make the verification, and at round end A is published as part of the block and participants can verify that none of their winning shares were rejected.

I don't think this should in any way affect how Bitcoin is used, it just solves this very important problem behind the scenes.

In case you're unaware, the most commonly known form cheating in mining pools, pool-hopping, has a solution waiting to be implemented. It should be possible for pool operators to publish their records in a way that guarantees they themselves don't cheat. And lie in wait can either be solved with my proposed change or significantly alleviated by other methods.

Welcome to Bitcoin. I don't think any of the exchanges currently offer such an option, but you can always simply find someone to lend you bitcoins in Forum/Marketplace or bitcoin-otc. You'll probably need either some reputation or collateral. (The generic you, I gather the personal you isn't interested in this.)

Mt Gox say on their site they'll allow options soon, which in my understanding satisfy the same need.

That's very exciting! Keep it light in information they can use to attack Bitcoin in case they don't like what you say .

Someone's going to have to ask this... Did you request to be paid in bitcoins?

Expected payout for mining = hashes * block reward / difficulty
Variance of payout = hashes * block reward^2 / difficulty
Standard deviation of payout = sqrt(hashes/difficulty) * block reward
Ratio between SD and expectation = sqrt(difficulty/hashes)

(In this notation I integrate the 2^32 factor into difficulty)

As Bitcoin grows, the total hashing capacity of the network will be much higher than that of an at-home miner (difficulty >> hashes), so his relative variance will be correspondingly high. Same goes for pools which are too small.

Or, more simply, when there are lots of miners, one with little capacity has a snowball's chance in hell to ever find a block.

Small pools will be fairly useless. Variance for small miners will be huge, and you need a large pool to get a remotely steady payout.

Wow, that's a nightmare scenario. We know that someone with >50% capacity can damage Bitcoin by reversing transactions, but I never imagined this hostile agent would be the supposedly "normal" miners. To prevent this from happening it's important to make sure that most of the capacity will belong to pools, who need to answer to their participants and thus less likely to carry such an attack.