You prune transactions only when there's already a long chain on top of the block in question, and you trust that the block was verified when it was fresh. So to tamper with the block you'll need to redo all the proof of work from then until now, which is unlikely (if you can do that, you can recreate the chain regardless of pruning transactions).

You do know that this has already been discussed to death, right? For starters have a look at https://en.bitcoin.it/wiki/Scalability.

1. Only a full node will need the entire block chain. End users will use a lightweight client that stores only relevant info, and uses the services of a full node to learn about transactions (but not to sign transactions).
2. Spent transaction will be pruned from the block chain, so storage requirement will be small.
3. 1.8 MB/s bandwidth is very reasonable.
4. Some of your math is off, eg it would be 50 TiB per year, not 51456.

I partially disagree. One of the selling points of Bitcoin is that it is a currency that has payment processing built-in. Centralized services like Visa will have their place, but it is a good thing if they are in competition with raw Bitcoin.

Risk can be kept at a low level while denominating price in BTC with some combination of selling bitcoins in advance, taking loans and buying options. These markets aren't very mature which is a problem, but Bruce could have found a creative solution if he wanted. I think denominating the price in USD is a strong negative signal and he should have spent the effort to avoid it. Even if it means making the price a bit higher - for many people the registration is about 1% of the cost of attendance so this pales in comparison to the signal.

Another problem is the bait-and-switch of listing the price in BTC, but then the order form is based on USD. Later he changed the listing to USD.

I again implore Bruce to update the agenda and the list of high-profile attendees.

PS. The reason I'm saying all this is that I really want to attend the "Bitcoin Conference & Worldwide Expo 2011 NYC", and went to some length to do so. But I don't want it to end up something else (a "meetup" or "LAN party" as some naysayers put it) due to poor organization and foresight, and this includes lack of attendance due to perception of said organization and foresight. Manny's comment that demand is strong is encouraging, but we need more.

I discuss this, among other things, in Analysis of Bitcoin pooled mining reward systems.

This is easily detectable with the proper client-side mining software. Everyone just needs to make sure that whenever they find a valid block, it is reported by the pool.

The problem is, of course, that people don't use the proper software (maybe it doesn't yet exist), or care much about trying to detect this.

If you use PPS it doesn't matter.

If you use a "PPS derivative" (by which I guess you mean *MPPS) you have the same problem, operator can hide found blocks, keep their reward to himself and misrepresent the pool's balance.

This is fixable with some protocol changes, adoption of decentralized metapools, and careful risk assessment (I'll write something about that last part pretty soon).

It says it right there in the info page of the conference - http://bitcoinme.com/index.php/bitcon-2011/ . "Check out the NEW VENUE"

Good catch. This story says it's a venue "upgrade", but I think they're just extrapolating as Bruce has been keeping radio silence lately. I really hope this is indeed an upgrade, due perhaps to high turnout (Bruce did say something about a plan B for the best case) and not something else.

Mining is about generating a certificate, easily verifiable without a centralized service, that work was done acknowledging a specific timeline of transactions. This is probably incompatible with external computing projects. If you can think of a way to combine them you'll have to be much more specific.

1.8MB, almost 6 months.

I got that, kind of, but I'm not buying the slippery slope argument. There's a fairly clear line between a global, annual (presumably) event, and other stuff.

Is that all this is? If this really is going to be a major event, Bruce should be able to get whoever does run bitcoin.org (Sirius?) to acknowledge it.

Bruce, some confirmation that everything you promised is indeed happening, and data on the number of participants, is in order.

I'll get to that too, eventually. But my already busy schedule just got a whole lot busier now that I've decided to attend the NYC conference. So it will take some time.

Why did the venue change, and why is there no update here or in the agenda (and why was this after I booked a hotel)?

Why is there no mention of the conference in bitcoin.org?

Distribution of what?

The total number of shares in a round follows the geometric distribution (the discrete version of the exponential distribution), with mean equal to the difficulty.

The number of blocks found among a given number of shares, follows the binomial distribution, or to an extremely good approximation, the Poisson distribution with mean (number of shares / difficulty).

Take a number uniformly distributed in [0,1]. Take the negative of the natural logarithm of it. Multiply by the mean. This gives you an exponentially distributed variable. Round up, this will give you approximately a geometric distributed one.

Bruce has a tendency to exaggerate, which is exactly why I think this list will be a useful resource, to me and others.

But to make it so, please keep meta-discussion to a minimum.

I'm struggling to find real data indicating if the conference is going to be half as big Bruce says it will.

If you intend to go, please make a post here saying so. If you're undecided, post what could influence your decision.

To keep this clean, please keep meta-discussion to a minimum.

My own status: Maybe, depending on who else will be there. Hence the post. I'm going.

One good thing about writing documentation is that when you have to explain your models, you need to think about them more carefully. And sometimes you find out that one of them is wrong.

I used to think that the existence of pool-hopping causes non-hoppers to earn, in the worst case, 70% of the normal reward. But I've now added to appendix B a derivation of this result, and it turns out my original model is wrong and it's actually 56.5%, equivalent to a 43.5% fee (and I've now confirmed it by simulation). All the more reason for miners in proportional pools to reconsider.

Ok, how about the new version?

That's what the bitcoin-otc WoT is for. Some assembly required.

A forum user-rating system could be useful (and was tried) but should be for rating a user's quality of posts.

I think p2pool's method isn't 100% hopping-proof, but I don't understand it well enough to be sure.

About that example, I wanted to point out that if there's 0.75 score left and the shares are 0.1 each, you use a score of 0.1 for the last 7 and 0.05 for the 8th.


You still need to tell me if the chapter marking are what you were looking for.

That's more or less the correct timeline for randomly stumbling upon a collision.

But, the currently used level of ECDSA being broken and someone being able to compute a private key for a given address, could be much sooner.