Qu’est qu’un Bitcoin?
A Bitcoin is a decentralized peer to peer electronic money. In essence, this is similar to a bank account, in the sense that your money is kept number in a database and the transfer system a number of account to another to make a transaction, except the system is decentralized database is stored on each participating computer simultaneously. Bitcoin is the first to be distributed as a currency, which has the result that its architecture has no man in the middle to take fee on each transaction you make, and that is not controlled by any organization or government .Emails allow you to send messages anywhere in the world. Skype does the same thing, but with telephone calls. Now there Bitcoin, allowing you to send money anywhere from anywhere without restrictions or borders for less than a cent per transaction. The system described in the paper by Satoshi Nakamoto of 2008 was sent to a list of email cryptography, and the original open source project was founded on January 3, 2009. For the first two years, the number of users has grown up end of 2010, following a Slashdot article in which he had an influx of new users and media attention and rapid price growth seen for the first time Bitcoin was exposed to the world. Since its inception, there are now more than one million users and 8.5 million existing units currently are together tens of millions of dollars. The distributed database Bitcoin Secure transfers between accounts (or, in the terminology of Bitcoin, addresses) using a mathematical algorithm known as digital signatures name and prévieny the problem known as double expense - send even bitcoins are two different people - by providing all transaction on a network that takes track of what bitcoins was spent and when to synchronize information on all participating machines. Since all transactions are distributed over the entire network, it is automatically public. Unlike regular bank, which preserves the privacy of consumers by keeping private transactions for Bitcoin, transparency, thereby keeping the identity of the owner of private addresses."Miner" for Bitcoins When a computer actively participating in the network, called a minor, taking charge of a new transaction and is satisfied with its authenticity, he added to the end of a list maintained collectively with dates and time of all known transactions call the "blockchain", confirming at the same time. Anyone else she tries to send the same corner again will be automatically rejected because the chain reveals that this area has already been spent. The process to add a block to the blockchain was designated to be really difficult, requiring much time and computing power to complete, so that it is essentially impossible to create a smuggling blockchain without more power calculation that the rest of the community Bitcoin network combined full. Each block has a value called ax, a mathematical figure generated data of a block using a deliberate function has to be referred to its convoluted result is essentially random and it is impossible to predict what the result will be before the calculation and the difficulty of creating a blocking increases in the sense that for each block be valid, its ax must be lower than a certain "target". Minors are then forced to make insignificant changes to blocks by trying different values of a dummy variable called "nonce" until a minor be lucky and see that the ax of one of his versions of blocks falls lower than the target, and there the blocks is added and the process begins again. The target is adjusted automatically so that, on average, a new block appears every 10 minutes. So the more that there are minors who engage in the business of mining, the harder it is for each minor to produce blocks.So what is the motivation of miners to spend every effort to try to produce blocks, if it takes time time and energy? The answer is that the person who manages to produce the block receives a reward. This award is in two parts. First, the block producer receives an abundant amount of bitcoins, it is agreed by the network (currently, this sum is 50 bitcoins; this value will be halved in December 2012 and about at every four years that follow to the number of bitcoins rewarded approach but never exceed 21 million). Second, all transaction costs that appear in the transactions included in the block are claimed by the block of the producer.So other than being important for maintaining transaction database, miner is also the only mechanical by any of bitcoins can be created and distributed to people in the Bitcoin economy. Miner CPU vs GPU withIn the early days of Bitcoin, it was easy for anyone to find new blocks using only standard CPU. But as more and more people began to undermine the difficulty greatly increased to the point that the average time for a CPU to find a single block has been increased in years. The only way to undermine that worth is to use a high-end graphics card with specialized software or attach a small pool.Bitcoin Some users may wonder why there is such a large difference in performance between the CPU vs GPU mining mining. A CPU is mainly designated to be an executor and make decisions, led by software. The CPUs are easily able to follow instructions like "if this happens, do that, otherwise do such a deal." On the other side, GPUs have been designated to be excellent to make processes video and less enforcement work. The process of the videos is very repetitive work, as it takes almost the same thing without stops to display a large number of pixels on the screen continuously. To make this work effectively, video processors are much more capable of doing repetitive work, as changing spot quickly. GPUs have a large sum of ALU (Arithmetic Unit / Logic), more than the CPU. This has the effect that it can make a bigger mathematical work in greater quantities than the CPU. One way to see this is for the CPU to imagine a small group of really smart kind that can do any task given to them quickly. A GPU is a big group of stupid people individually are not too smart or fast, but can be driven to do repetitive task and that collectively they can be more productive simply because of their large number. Try several axes quickly - the process behind the Bitcoin mining - is a repetitive task really very suitable for the GPU, because it is almost the same work each test but with the change of a single number (called the "nonce" ) in the data that are chopping. And that is why, soon, a GPU can erode faster than a CPU Bitcoins. Miner for bitcoins require any decision - it is a repetitive mathematical task for a computer. The only decision he had to make in the Bitcoin mining is: Do I have a valid or invalid block. This is a great workload to run on a GPU.