Bitcoin is an experimental new digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin is also the name of the open source software which enables the use of this currency.
Bitcoin’s public ledger (the ‘block chain’) was started on January 3rd, 2009 at 18:15 UTC presumably by Satoshi Nakamoto. The first block is known as the genesis block. The first transaction recorded in the first block was a single transaction paying the reward of 50 new bitcoins to its creator.
Bitcoin used as currency explained
Alice wants to buy the Alpaca socks Bob has for sale. In return, she must provide something of equal value to Bob. The most efficient way to do this is by using a medium of exchange that Bob accepts which would be classified as currency. Currency makes trade easier by eliminating the need for coincidence of wants required in other systems of trade such as barter. Currency adoption and acceptance can be global, national, or in some cases local or community-based.
What are bitcoins?
Bitcoins are the unit of currency of the Bitcoin system. A commonly used shorthand for this is “BTC” to refer to a price or amount (eg: “100 BTC”). There are such things as physical bitcoins, but ultimately, a bitcoin is just a number associated with a Bitcoin Address. A physical bitcoin is simply an object, such as a coin, with the number carefully embedded inside. See also an easy intro to bitcoin.
Where does the value of Bitcoin stem from? What backs up Bitcoin?
Bitcoins have value because they are useful and because they are scarce. As they are accepted by more merchants, their value will stabilize. See the list of Bitcoin-accepting sites. When we say that a currency is backed up by gold, we mean that there’s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.
It’s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn’t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn’t make anything valuable. For example, your fingerprints are scarce, but that doesn’t mean they have any exchange value.
Sending and Receiving Payments
Why do I have to wait 10 minutes before I can spend money I received?
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. You can see how long all other recent transactions have taken here: BitcoinStats.org.
Blocks (shown as “confirmations” in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it’s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!
Do I need to configure my firewall to run bitcoin?
Bitcoin will connect to other nodes, usually on tcp port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your bitcoin client to connect to many nodes. Testnetuses tcp port 18333 instead of 8333.
If you want to restrict your firewall rules to a few ips, you can find stable nodes in the fallback nodes list.
How does the peer finding mechanism work?
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it’s aware of for use in the future. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn’t work it falls back to a build-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.
What is mining?
Mining is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system. Technically speaking, mining is the calculation of a hash of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a nonce. If the hash value is found to be less than the current target (which is inversely proportional to the difficulty), a new block is formed and the miner gets the newly generated Bitcoins (50 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.
Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?
There are two questions in here. Let’s look at them separately.
Could miners gang up and give themselves money?
Mining itself is the process of creating new blocks in the block chain. Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block. New blocks are ‘mined’, or rather, generated, by Bitcoin clients correctly guessing sequences of characters in codes called ‘hashes,’ which are created using information from previous blocks. Bitcoin users may download specialized ‘mining’ software, which allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block. Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based. The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information. Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease. These things make Bitcoin very hard to fool.
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency. Each correct guess yields, at present, fifty Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money. Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.
Therefore, first answer is a vehement “yes” – no only can miners collude to get more money, Bitcoin is designed to encourage them to do so. Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.
A recent article in Forbes written by Andy Greenberg addressed the Wikileaks association with Bitcoin transactions. http://www.forbes.com/sites/andygreenberg/2011/06/14/wikileaks-asks-for-anonymous-bitcoin-donations/
Can Bitcoin be the new state of currency to come? For more information go to www.bitcoin.org