Try index.php. Anyway, judging by the fact that the 404 error message is hosted on filenetworking.com, which has the same IP address (184.172.150.4) and nameservers (NS2849.HOSTGATOR.COM and NS2850.HOSTGATOR.COM) as cryptocoin.info even though the two domain names were registered through two different companies (Dotster, Inc. and Domain.com, LLC), plus the fact that the cryptocoin.info domain was recently (2 April 2012) changed for no obvious reason, I'm guessing it was hacked.

To elaborate, the wallet from which you spend the coins will generate a hidden "change" address which will not be present on the other wallet*, causing you to lose a few coins (actually, you don't really lose them, they'll just only be visible (and spendable) from one wallet and not the other). However, if you always create a new copy of your wallet file after any time you spend some coins or create a new address, and remember to always transfer this up-to-date wallet file before you do anything else, there'll be no problem.

*Actually, I think the standard client generates a certain number of change addresses in advance for the sole purpose of avoiding this exact problem, but I'm not 100% sure. Best to play it safe and keep your wallet files synchronised.

But just how much of that 904,380.25 BTC is simply people sending coins to themselves for legitimate (change) or illegitimate (laundering) purposes? You don't know. Nobody knows. In any case, 10% of the entire economy is more than a significant fraction, and unless you can show evidence that some other use of bitcoins accounts for more than that, then I stand by what I said.

Difficulty is the maximum possible hash target divided by the current hash target. The average time to find a block (in seconds) is equal to the current difficulty times 2^32 (4,294,967,296) divided by your hashrate (in hashes per second) (eg, if your hashrate is 1 Ghash/s = 1,000,000,000 hashes per second then the average time it will take you to find a block is (1,626,553 x 4,294,967,296 / 1,000,000,000 = 6,985,992 seconds = 80 days).

Since the difficulty is adjusted so that miners find blocks on average once every 10 minutes (600 seconds), the total hashpower of the network is equal to the difficulty times 2^32 divided by 600 (eg, 1,626,553 x 4,294,967,296 / 600 = 11,643,319,900,351 hashes per second = 11.6 terahashes per second). That's how much hashpower you need to pull off a 51% attack. Good luck!

I thought the vast majority of bitcoins were used to buy dollars. Which were then used to buy bitcoins again. Sometimes at a profit (and sometimes not). Hopefully this situation will change as bitcoins become more widely accepted.

The idea of mining is to calculate a cryptographic hash of a block (a block is basically just a list of recent transactions, a hash of the previous block (so you can't prepare fraudulent blocks in advance), and some other stuff) such that the value of the hash is lower than a predetermined target. If it is, you win: your block gets included in the block chain and you receive the block reward (currently 50 BTC) as well all the transaction fees associated with that block. If the hash doesn't come under the target, you lose, and you have to try again by changing a small piece of data in the block (called the nonce) which causes the whole hash to change in a random way. The key point about a cryptographic hash is that it's impossible to predict what effect changing the nonce (or any other part of the data) will have on the hash: the only way to get a hash that meets the target is to try every possible nonce (a typical mining system is capable of trying millions per second) until you find one that works. This is key to the security of Bitcoin: it's impossible for anyone to introduce a fraudulent block without first using a ton of computing power to find one that meets the hash target. Not only that, they'd need (on average) more computing power than the rest of the network combined, because if anyone else finds a real block first, all the effort trying to produce a fraudulent block is wasted.

This code just calls the hashing function on the blocks, there's nothing special about it.

It won't take anyone by surprise, and the blockchain won't need saving. There's nothing to save it from. There's just not a whole lot of damage you can actually do with 51% of the hashpower. Block other people's transactions? The transactions will get through the instant you lose your 51%. Double-spend your coins? You'd need to double-spend a lot of coins at once to make it worth the amount of money a 51% attack would cost, because it only works once: as soon as your coins are first double-spent, everyone will realise that the network is compromised and will refuse to trust any future large transactions until it's clear the attack is over, at which point it's business as usual again. No precautionary measures are needed because the network is already designed to handle this threat.

Of course it's possible to lend bitcoins. It's also possible to have fractional reserve banking with bitcoins. Neither of these is any way against what bitcoin represents. Bitcoin represents a currency, nothing more.

That only works if change gets sent back to your original address instead of a new address, otherwise the public key will show less money than is actually in the wallet. And there's no surer way of scaring people than telling them they have less money than they thought they did:
"Okay, so I'll send 0.5BTC and... wait, why'd my balance just go down by 20BTC? I only sent 0.5BTC!! Didn't I? FFFFUUUUUU!!!"

A better idea is for the machine to display a QR Code, you scan it and send your bitcoins to that address (using your own device), then you get your cash. Putting your private key data on a public machine is kinda dumb. The problem is that an ATM can't afford to wait several minutes for confirmation (though there are solutions).

Thanks, that fixes it. I am curious why you thought a timeout of only 1 second would work in all cases; not everyone has cable or even DSL for that matter (at least not everyone in Australia ) This really needs to made configurable. And I take it that you'll be testing Internet connectivity by connecting to the actual Bitcoin network, rather than Google, once you've got the actual networking side done?

Sorry, but as with real wallets, if you lose your Bitcoin wallet, all the money in it is as good as gone unless you can find it again. Have you tried looking under the sofa cushions? Seriously though, how did you manage to lose it?

I've built Armory (0.70-beta)-alpha on MEPIS 11 (a distro based on Debian 6) and I'm having a major problem and few minor problems.

The major problem is that most of the time it'll flat-out refuse to start in online mode complaining that it doesn't have an Internet connection. My Internet connection has a highly variable latency (sometimes it's around 50ms, sometimes it's 5 seconds or even more) due to wireless reception issues, could that be the problem? If so, a higher (preferably configurable) timeout and/or a "Retry" button on the message box would be in order.

The minor problems are that the windows are just not wide enough to see everything without scrolling, and I have to make them a few pixels wider (or else maximise the window). But the program doesn't remember its window sizes when I quit (nor does it remember if it was maximised), so I have to do this every single time, which is most annoying.

Also, the advanced encryption options only appear when creating a new wallet. When encrypting a wallet after it's been created, the advanced encryption options don't appear. Is there no way to change the advanced encryption options for an existing wallet?

One more thing which isn't really a problem as such, but may be a possible source of confusion for new users, is that the "Receive Bitcoins" button creates a new address (without even asking for confirmation), while the same button on the Satoshi client displays a list of existing addresses, with an option to create new ones. I think it would be better to have a dialog asking the user whether they want to select an existing address (assuming the wallet has at least one address already), or create a new one (yes, you can put a "Don't ask me again" checkbox to avoid annoying those who actually like the present behaviour).

Also, I have a dark colour scheme too, and I have the same problem that dooglus has. Half the text is either light grey on white or dark red/green on dark grey. Argh, my eyes! One option (which shouldn't be too difficult) is to algorithmically generate colours based on the system colours, eg (pseudocode): GreenText = (SystemText * RGB(0.0, 1.0, 0.0)) + RGB(0.0, 0.25, 0.0); to get a dark green on systems with black text and a bright green on systems with white text, etc.

Oh, and the issue with running multiple instances of Armory should definitely be a high priority. Merely telling people not to do that is not a satisfactory solution, given the consequences.

Yes, that does make a bit of a difference. I don't know exactly how much of a difference, but... yeah. Oh, I should also point out that I don't usually run all of my PCs all the time (as is typical for a mining operation), for exactly this reason. A single PC has lower power requirements, but correspondingly lower returns. You can't really do much with just one PC. Generally you want several PCs each with multiple GPUs, or else some kind of specialised hardware. Not to mention some means of powering the whole operation that costs less than the bitcoins you're mining (this is where the whole plan falls apart, at least in Australia).

But your PC isn't idling during mining, and that's the problem. Your system needs to exert some serious computing power, and you need some serious cooling to go with it. All up, my PCs draw 3-4 kW for around $16-$22 per day. I haven't actually tried mining with my system, but by my guesstimate it should do about 2Ghash/s, and mine about 1BTC per day. Not even worth trying.

Nobody's trying to hide anything. Scammers and criminals are attracted to anything with money involved, everybody knows that, and Bitcoin is no exception. I think the general public does (or at least, should) understand the importance of protecting themselves, given the number of scams involving fiat currency.

In my experience, people (especially people unfamiliar with e-commerce) are worried about two things when buying things online: "What if they steal my money?" and "What if they steal my identity?" With Bitcoin, the second question disappears completely, which I think is one of it's major selling points. The first question is (at least partly) answered by dealing only with reputable merchants and escrow services, which is what most people try to do anyway when using credit cards online, if only because having to reverse credit card transactions is a pain.

I've got the equipment (a bunch of gaming machines each with one or two high-end RadeonHD cards), I just wish we had cheap enough electricity to make mining even close to profitable. With electricity prices being what they are, the very idea of running all these machines 24/7 at 100% load makes me cringe. A more specialised setup (eg FPGA) would be cheaper, but still nowhere near cheap enough.

Trust is always required, and it will always be abused by scammers, regardless of whether you shop with bitcoins, cash, or credit. Either you have to trust that the seller will give you the goods (caveat emptor), or the seller has to trust that you won't reverse the transaction after receiving the goods (caveat vendor). Bitcoin follows the former model, credit cards follow the latter model. You can't have it both ways.

As for major financial institutions being hacked, it's not just specific to Bitcoin: regular banks and payment processors get hacked, companies storing customer's credit card details get hacked, etc. It happens all the time. You almost can't even turn on the news without hearing about something like that happening. So I don't think Bitcoin's negative publicity is any worse than any other financial system.

How to generate positive publicity for Bitcoin is a tricky question. I don't think it's mature enough at this stage to go mainstream. Definitely we should wait until the first block reward halving, since that's the big question on everyone's mind right now (and is related to the all-too-common question of what happens when block rewards cease completely) and nobody really knows what effect it will have on the market. Assuming halving the block reward doesn't cause any major disruption, there'll be a lot less uncertainty about the future of Bitcoin, and that will put it in a much stronger position for widespread adoption. Then we can start thinking about publicity.

Recycling metal is almost as expensive as mining it out of the ground. Add to that the cost of dismantling the ship (which is a huge job, requiring a drydock facility), and it's just not worth it. Metal has to become a lot more valuable in order for recycling a ship to become profitable.

Hi, I'm Foxpup, from Australia. I recently found out about Bitcoin and I think it's the greatest thing to happen to the Internet since PGP.