Understanding Bitcoin

Bitcoin is a digital and global money system currency. It allows people to send or receive money across the internet, even to someone they don't know or don't trust. Money can be exchanged without being linked to a real identity. The mathematical field of cryptography is the basis for Bitcoin's security.

What is difference between Bitcoin & Online Money?

One of the differences between using bitcoin and using regular money online is that bitcoin can be used without having an internet connection 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. Bitcoin does not keep track of users; it keeps track of addresses where the money is.

What does bitcoin addresses comprise of?

Each address has two important pieces of cryptographic information, or keys: a public one and a private one. The public key, which is what the "bitcoin address" is created from, is similar to an email address; anyone can look it up and send bitcoins to it. The private address, or private key, is similar to an email password; only with it can the owner send bitcoins from it. 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.

What is the role of Cryptography in Bitcoin?

Bitcoin uses Asymmetric Keys. 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.

Each user 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. 

What is Block Chain?

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.

What is bitcoin Mining?

To generate a bitcoin, a miner must solve a math problem. However, the difficulty of the math problem depends on how many people are mining for bitcoin at the moment. Because of how complicated the math problems usually are, they must be calculated with very powerful processors. 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.

What are QR Codes?

QR codes are a group of black and white boxes that are similar to barcodes. Barcodes have one dimension of information, while QR codes have two (horizontal and vertical). Barcodes are a row of lines, and QR codes are a grid of squares. Bitcoin uses QR codes because they can store a lot of information in a small space, and a camera such as a smartphone can read them. The two QR codes on the Bitcoin note are the public and private addresses, and can be scanned with a number of online tools.

What are Exchanges?

Everyone in the Bitcoin network is considered a peer, and all addresses are created equal. All transactions can take place solely from peer to peer, but a number of sites exist to make these transactions simpler. These sites are called exchanges. Exchanges provide tools for dealing in Bitcoin. Some allow the purchase of Bitcoin from external accounts, and others allow trading with other cryptography-based currencies like Bitcoin. Most exchanges also provide a basic "wallet" service.

What is Wallet?

Wallets provide a handy way to keep track of all of a user's public and private addresses. Because addresses are pseudo-anonymous, anyone can have as many addresses as they want. This is useful for dealing with multiple people, but it can get complicated to manage multiple accounts. A wallet holds all of this information in a convenient place, just like a real wallet would. A backup of a wallet prevents 'losing' the bitcoins.

How does it work?

As a new user, you can get started with Bitcoin without understanding the technical details. Once you've installed a Bitcoin wallet on your computer or mobile phone, it will generate your first Bitcoin address and you can create more whenever you need one. You can disclose your addresses to your friends so that they can pay you or vice versa. In fact, this is pretty similar to how email works, except that Bitcoin addresses should be used only once.

The block chain is a shared public ledger on which the entire Bitcoin network relies. All confirmed transactions are included in the block chain. It allows Bitcoin wallets to calculate their spendable balance so that new transactions can be verified thereby ensuring they're actually owned by the spender. The integrity and the chronological order of the block chain are enforced with cryptography.

A transaction is a transfer of value between Bitcoin wallets that gets included in the block chain. Bitcoin wallets keep a secret piece of data called a private key or seed, which is used to sign transactions, providing a mathematical proof that they have come from the owner of the wallet. The signature also prevents the transaction from being altered by anybody once it has been issued. All transactions are broadcast to the network and usually begin to be confirmed within 10-20 minutes, through a process called mining.

Mining is a distributed consensus system that is used to confirm pending transactions by including them in the block chain. It enforces a chronological order in the block chain, protects the neutrality of the network, and allows different computers to agree on the state of the system. To be confirmed, transactions must be packed in a block that fits very strict cryptographic rules that will be verified by the network. These rules prevent previous blocks from being modified because doing so would invalidate all the subsequent blocks. Mining also creates the equivalent of a competitive lottery that prevents any individual from easily adding new blocks consecutively to the block chain. In this way, no group or individuals can control what is included in the block chain or replace parts of the block chain to roll back their own spends.