File:Bitcoin explained in 3 minutes. It allows people to send or receive money across the bitcoin wallet wikipedia, even to someone they don’t know or don’t trust.
Money can be exchanged without being linked to a real identity. A Bitcoin address, or simply address, is an identifier of 26-35 alphanumeric characters, beginning with the number 1 or 3, that represents a possible destination for a bitcoin payment. Addresses can be generated at no cost by any user of Bitcoin. For example, using Bitcoin Core, one can click “New Address” and be assigned an address. It is also possible to get a Bitcoin address using an account at an exchange or online wallet service.
One of the differences between using bitcoin and using regular money online is that bitcoin can be used without having to link any sort of real-world identity to it. Unless someone chooses to link their name to a bitcoin address, it is hard to tell who owns the address. Each address has two important pieces of cryptographic information, or keys: a public one and a private one. Because of this, it is very important that this private key is kept secret.
To send bitcoins from an address, you prove to the network that you own the private key that corresponds to the address, without revealing the private key. This is done with a branch of mathematics known as public key cryptography. A public key is what determines the ownership of bitcoins, and is very similar to an ID number. If someone wanted to send you bitcoins, all you would need to do is supply them your bitcoin address, which is a version of your public key that is easier to read and type. For example, if Bob has 1 bitcoin at the bitcoin address “ABC123,” and Alice has no bitcoins at the bitcoin address “DEF456,” Bob can send 0. As soon as the transaction is processed, Alice and Bob both have 0.
Anyone using the system can see how much money “ABC123” has and how much money “DEF456” has, but they cannot tell anything about who owns the address. In the example above, “ABC123” and “DEF456” are the bitcoin addresses of Bob and Alice. But Bob and Alice each have a second key which only they individually know. This is the private key, and it is the “other half” of a Bitcoin address. The private key is never shared, and allows the owner of the bitcoins to control them.
However, if the private key is not kept secret, then anyone who sees it can also control and take the bitcoins there. This happened on live TV when Bloomberg’s Matt Miller accidentally showed a private key to viewers. The money was taken immediately. Sites or users using the Bitcoin system are required to use a global database called the blockchain. The blockchain is a record of all transactions that have taken place in the Bitcoin network. It also keeps track of new bitcoins as they are generated.
With these two facts, the blockchain is able to keep track of who has how much money at all times. To generate a bitcoin, a miner must solve a math problem. However, the difficulty of the math problem depends on how many people are buying bitcoin at the moment. These processors can be found in CPUs, graphics cards, or specialized machines called ASICs. The process of generating the bitcoins is called mining. People who use these machines to mine bitcoins are called miners. Miners either compete with one another or work together in groups to solve a mathematical puzzle.
The first miner or group of miners to solve the particular puzzle are rewarded with new bitcoins. The puzzle is determined by the transactions being sent at the time and the previous puzzle solution. This means the solution to one puzzle is always different from the puzzles before. Attempting to change an earlier transaction, maybe to fake bitcoins being sent or change the number of someone’s bitcoins, requires solving that puzzle again, which takes a lot of work, and also requires solving each of the following puzzles, which takes even more work.
This means a bitcoin cheater needs to outpace all the other bitcoin miners to change the bitcoin history. This makes the bitcoin blockchain very safe to use. A paper printable bitcoin wallet consisting of one bitcoin address for receiving and the corresponding private key for spending. QR codes are a group of black and white boxes that are similar to barcodes. Barcodes are a row of lines, and QR codes are a grid of squares. The two QR codes on the Bitcoin note are the public and private addresses, and can be scanned with a number of online tools.