When you generate a new bitcoin address, it only takes disk space on your own computer (like 500 bytes). It's like generating a new PGP private key, but less CPU intensive because it's ECC. The address space is effectively unlimited. It doesn't hurt anyone, so generate all you want.

The root problem with conventional currency is all the trust that's required to make it work. The central bank must be trusted not to debase the currency, but the history of fiat currencies is full of breaches of that trust.

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Announcing version 0.3 of Bitcoin, the P2P cryptocurrency! Bitcoin is a digital currency using cryptography and a distributed network to replace the need for a trusted central server. Escape the arbitrary inflation risk of centrally managed currencies! Bitcoin's total circulation is limited to 21 million coins. The coins are gradually released to the network's nodes based on the CPU power they contribute, so you can get a share of them by contributing your idle CPU time.

I wish rather than deleting the article, they put a length restriction. If something is not famous enough, there could at least be a stub article identifying what it is. I often come across annoying red links of things that Wiki ought to at least have heard of. The article could be as simple as something like: "Bitcoin is a peer-to-peer decentralised /link/electronic currency/link/." The more standard Wiki thing to do is that we should have a paragraph in one of the more general categories that we are an instance of, like Electronic Currency or Electronic Cash. We can probably establish a paragraph there. Again, keep it short. Just identifying what it is.

I wish rather than deleting the article, they put a length restriction. If something is not famous enough, there could at least be a stub article identifying what it is. I often come across annoying red links of things that Wiki ought to at least have heard of. The article could be as simple as something like: "Bitcoin is a peer-to-peer decentralised /link/electronic currency/link/." The more standard Wiki thing to do is that we should have a paragraph in one of the more general categories that we are an instance of, like Electronic Currency or Electronic Cash. We can probably establish a paragraph there. Again, keep it short. Just identifying what it is.

To compensate for increasing hardware speed and varying interest in running nodes over time, the proof-of-work difficulty is determined by a moving average targeting an average number of blocks per hour. If they're generated too fast, the difficulty increases.

We should have a gentleman's agreement to postpone the GPU arms race as long as we can for the good of the network. It's much easer to get new users up to speed if they don't have to worry about GPU drivers and compatibility. It's nice how anyone with just a CPU can compete fairly equally right now.

Since 2007. At some point I became convinced there was a way to do this without any trust required at all and couldn't resist to keep thinking about it. Much more of the work was designing than coding. Fortunately, so far all the issues raised have been things I previously considered and planned for.

The average total coins generated across the network per day stays the same. Faster machines just get a larger share than slower machines. If everyone bought faster machines, they wouldn't get more coins than before.

Right, nodes keep transactions in their working set until they get into a block. If a transaction reaches 90% of nodes, then each time a new block is found, it has a 90% chance of being in it.

Simplified Payment Verification is for lightweight client-only users who only do transactions and don't generate and don't participate in the node network. They wouldn't need to download blocks, just the hash chain, which is currently about 2MB and very quick to verify (less than a second to verify the whole chain). If the network becomes very large, like over 100,000 nodes, this is what we'll use to allow common users to do transactions without being full blown nodes. At that stage, most users should start running client-only software and only the specialist server farms keep running full network nodes, kind of like how the usenet network has consolidated. SPV is not implemented yet, and won't be implemented until far in the future, but all the current implementation is designed around supporting it.

If a merchant actually has a problem with theft, they can make the customer wait 2 minutes, or wait for something in e-mail, which many already do. If they really want to optimize, and it's a large download, they could cancel the download in the middle if the transaction comes back double-spent. If it's website access, typically it wouldn't be a big deal to let the customer have access for 5 minutes and then cut off access if it's rejected. Many such sites have a free trial anyway.

It's not a problem if transactions have to wait one or a few extra cycles to get into a block.

Instantant non-repudiability is not a feature, but it's still much faster than existing systems. Paper cheques can bounce up to a week or two later. Credit card transactions can be contested up to 60 to 180 days later. Bitcoin transactions can be sufficiently irreversible in an hour or two.

The proof-of-work also solves the problem of determining representation in majority decision making. If the majority were based on one-IP-address-one-vote, it could be subverted by anyone able to allocate many IPs. Proof-of-work is essentially one-CPU-one-vote. The majority decision is represented by the longest chain, which has the greatest proof-of-work effort invested in it. If a majority of CPU power is controlled by honest nodes, the honest chain will grow the fastest and outpace any competing chains. To modify a past block, an attacker would have to redo the proof-of-work of the block and all blocks after it and then catch up with and surpass the work of the honest nodes. We will show later that the probability of a slower attacker catching up diminishes exponentially as subsequent blocks are added.

We should have a gentleman's agreement to postpone the GPU arms race as long as we can for the good of the network. It's much easer to get new users up to speed if they don't have to worry about GPU drivers and compatibility. It's nice how anyone with just a CPU can compete fairly equally right now.

That would be nice at point-of-sale. The cash register displays a QR-code encoding a bitcoin address and amount on a screen and you photo it with your mobile.

I'm happy if someone with artistic skill wants to contribute alternatives. The icon/logo was meant to be good as an icon at the 16x16 and 20x20 pixel sizes. I think it's the best program icon, but there's room for improvement at larger sizes for a graphic for use on websites. It'll be a lot simpler if authors could make their graphics public domain.

Excellent choice of a first project, nice work. I had planned to do this exact thing if someone else didn't do it, so when it gets too hard for mortals to generate 50BTC, new users could get some coins to play with right away. Donations should be able to keep it filled. The display showing the balance in the dispenser encourages people to top it up. You should put a donation bitcoin address on the page for those who want to add funds to it, which ideally should update to a new address whenever it receives something.