35

I think the premise of the question is not correct. The work is not useless, it secures the transactions. The public hash chain ensures that Bitcoins can only be spent once. The mechanism piles computations on top of legitimate transactions so that the recipient knows that an attacker would need at least as much computing ability to "undo" the transaction. ...


25

Here's the basic idea of blind signing in Chaumian e-cash: Let's suppose that a central issuer (Chaumian e-cash is centralised) has an account in my name with a value of 10 dollars. In order to "withdraw" this money as 1-dollar "bills" I begin by generating ten random serial numbers, each long enough that I can be reasonably sure no one else will generate ...


24

Colored coins are a method to track the origin of bitcoins, so that a certain set of coins can be set aside and conserved, allowing a party to acknowledge them in various ways. Such coins can be used to represent arbitrary digital tokens, such as stocks, bonds, smart property and so on. The colored coins protocol is decentralized just like Bitcoin, but the ...


17

NooShare is an idea for: a decentralised ledger similar to Bitcoin with the novel feature that its proofs of work are iterations of essentially arbitrary Markov-Chain Monte-Carlo (MCMC) chains, the scheduling of which can be purchased using the currency itself. It is a novel economic basis for sharing fallow computational resources. I don't know ...


16

No, you can't prevent fractional reserve banking technically. For example, IOUs can circulate just like Bitcoins and there's no technical means to stop it. Essentially, anything worth X Bitcoins (once risk and the like are factored in) can act just like X Bitcoins, even if it's not X Bitcoins. And since it's not Bitcoins, nothing Bitcoins can do can stop it. ...


15

The primary advantages are: Speed and price. You can transfer money anywhere in the world within minutes with negligible fees. No central authority. Bitcoin is not dependent on any company or government to maintain its value. You can start accepting bitcoins instantaneously, without setting up merchant accounts, buying credit card processing hardware, etc. ...


14

The problem is that no one has come up with a proof-of-work system based on useful work that also: Generates easily verifiable solutions Can have the difficulty of finding a solution adjusted For example, if the system were searching for prime numbers, the solutions would take a long time to verify as being prime. The difficulty of finding the next prime ...


14

This is a 51% attack where the attacker sets the block timestamps artificially to lower the difficulty, allowing him to profit more coins than his hash rate would warrant. It works because the difficulty adjustment formula is based purely on timestamps that can be chosen quite freely by the attacker. In particular, the timestamps are not required to be in ...


13

Flattr is a social micropayments system. Bitcoin is a currency. There is no reason the two could not be integrated together, pay with bitcoins and then share the bitcoins out using the same method as flattr. In fact, I would go as far as saying this would be an excellent idea due to lack of transaction fees and friction for small amounts. Flattr is the ...


13

It depends entirely how much those alternate block-chains get utilized. In the recent examples of ixcoin and i0coin, a small portion of btc miners and users switched over, sold their stash and went right back to bitcoin. It's essentially a case of network effect - whichever block-chain has the most users will be the most attractive to new users, and those ...


13

There are a number of other cryptocoins in use alongside Bitcoin, the most notable are: Testnet Bitcoins (used only for testing Bitcoin applications, but they are an important mention) - they work exactly the same as Bitcoins. Namecoins - coinage used as a distributed naiming system blockchain. Their most notable feature is that they can be merged mined ...


12

The bitcoin concept has no method to limit anything to a single entity. I am one person yet on bitcon network I have multiple addresses, I have multiple wallets which contain multiple addresses, I make up multiple nodes, I have multiple rigs with multiple GPU each, I use multiple IP addresses. Everything about the bitcon network was designed to allow such ...


10

Have you tried understanding why you have that desire? It might help you understand more about what makes you tick. You might like to try mining Litecoins, or even on the Bitcoin Testnet. Or, you could try some Bitcoin mining with the Eligius pool, which from memory will pay out any amount after 2 weeks (whereas most pools have a minimum payout). If you can ...


10

If scripts were Turing-complete, you could construct a fairly short script that took an extremely long time to run (a la the Busy Beaver) or contained an infinite loop. This would tend to result in a denial of service against everyone on the network, when they tried to verify the transaction. And there would be no general way to tell whether a script ...


9

A Bitcoin or Litecoin address consists of: a prefix byte a 160-bit hash of a public key a 32-bit checksum all base-58 encoded. Bitcoin and Litecoin use different prefix bytes; this is why most Bitcoin addresses start with 1, while most Litecoin addresses start with L. When you use a Bitcoin client to try to send money to an address, it should perform a ...


9

99% of altcoins claim an "innovation" that is broken or unproven. I would say that the first thing to do is look at unique codebases that aren't based on Bitcoin, which basically means (besides Bitcoin) you should look at Ethereum, Ripple, NXT, Monero, BitShares. Then if you're bored, PeerCoin / NuBits and Lisk. Once you are done with those you can look at ...


8

It is likely that blockchain-based currencies like Bitcoin are a natural monopoly. It is most beneficial for users to own and accept in trade the most popular currency, as they will have the greatest number of opportunities to do business with it. This is referred to as a network effect. There are also additional costs and risks associated with owning and ...


8

Regarding the specific questions about your website, it is up to you to decide which payment methods to accept. If you want to accept small payments, Paypal and credit cards may not interest you because of their high fees. So both Flattr and Bitcoins can replace Paypal as an alternative for cheaper micro-payments. As for advantages/disadvantages: Flatter ...


8

Some discussions around how to make it more useful https://en.bitcoin.it/wiki/Intrinsic_worth_brainstorming https://bitcointalk.org/index.php?topic=11834.0


8

At least one group has at least claimed to develop a voting system based on Bitcoin. http://www.newscientist.com/article/mg21328476.500-bitcoin-online-currency-gets-new-job-in-web-security.html According to the article: The pair have used their method, known as CommitCoin, to close a loophole in a voting system they helped develop. In the Scantegrity ...


8

The alternative currency Geist Geld is experimental and is trying to approach a maximum block rate (that's currently achievable), and has apparently settled upon a target block rate of 1 block per 15 seconds. However, the block rate doesn't necessarily make a substantial difference to how you would use a currency as you could still consider a small ...


8

BTC-E currently offers trading pairs of BTC/USD, BTC/RUB, SC/BTC, SC/USD, GG/BTC, TBX/BTC, FBX/BTC, LTC/BTC, LTC/USD, RUC/BTC, RUC/USD, RUC/RUB, NMC/BTC and RUB/USD


8

Those running a miner against a pool don't. The pool operator would need both. As stated in the comments below, normal users of the alternate system will not need the bitcoin chain but will need the alternate chain, and normal users of bitcoin will need the bitcoin chain but not the alternate chain. Once the block is mined, nobody cares what other chains ...


8

What you are describing there is a client that is a hybrid of Bitcoin and something else. For instance there is nothing to stop you starting ManishCoin and writing a ManishBitcoinSuperClient. If you can get enough people to believe in ManishCoin then it becomes a useful currency.


8

Nothing stops this at all. You can start your own right now, removing the 21M limit or adopting whatever rules you want, and mine as many coins as you like. Likewise, you can sit down at your printer, and print lots of $100 bills with your own portrait, and invent whatever rules you want as to how they can be spent. The question in both cases is whether ...


8

This is really asking about basic trading economics: if I have some new product X, what price does it have? I can set a price and see if anyone buys it. If not, I might lower the price or auction it to see what someone might pay for it. That is the starting value, but it doesn't really mean much as it hasn't been field-tested (so to speak). If others think ...


7

Assume for a second that we found a proof of work algorithm that had all of the good properties of sha256, but was also useful for SETI and maintaining world peace. Now suppose a group of miners collectively have more than 51% of the hashing power. In which of the following scenarios are they more likely to collude to double spend via a 51% attack: A) When ...


7

Sidestepping the comments about whether or not Namecoin is a fork or a separate project or whether bitcoin is an investment or a currency, I'll address the direct question asked: Is there a way to easily and automatically purchase several crypto-currencies at once? Not at present time, no. Bitcoin (and its forks) is a very young project, though, and I'm ...


7

What you're talking about is actually two separate concepts. A "Bitcoin Address" is not a keypair, it does not have public and private components. The Address is derived from the public portion of the key pair and is almost always expressed as a Base58 string. Firstbits is merely a way to look up addresses. When you enter someone's "firstbits" address at ...


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