The peer-to-peer network structure in cryptocurrencies is structured according to the consensus mechanism that they are utilizing. For cryptos like Bitcoin and Ethereum which uses a normal proof-of-work consensus mechanism (Ethereum will eventually move on to Proof of Stake), all the nodes have the same privilege. The idea is to create an egalitarian network. The nodes are not given any special privileges, however, their functions and degree of participation may differ. There is no centralized server/entity, nor is there any hierarchy. It is a flat topology.
Proof of Work is a system that requires some work from the service requester, usually meaning processing time by a computer. Producing a proof of work is a random process with low probability, so normally a lot of trial and error is required for a valid proof of work to be generated. When it comes to Bitcoins, hash is what serves as a proof of work.
For all its complexity, blockchain’s potential as a decentralized form of record-keeping is almost without limit. From greater user privacy and heightened security, to lower processing fees and fewer errors, blockchain technology may very well see applications beyond those outlined above. Here are the selling points of blockchain for businesses on the market today.
Though each bitcoin transaction is recorded in a public log, names of buyers and sellers are never revealed – only their wallet IDs. While that keeps bitcoin users’ transactions private, it also lets them buy or sell anything without easily tracing it back to them. That’s why it has become the currency of choice for people online buying drugs or other illicit activities.
Satoshi's anonymity often raises unjustified concerns because of a misunderstanding of Bitcoin's open-source nature. Everyone has access to all of the source code all of the time and any developer can review or modify the software code. As such, the identity of Bitcoin's inventor is probably as relevant today as the identity of the person who invented paper.

Bitcoin runs on the PoW model. What happens with PoW is that cryptocurrency miners (a fancy term for people with really high-powered computers) compete against one another to solve complex mathematical equations that are a result of the encryption protecting transactions on a blockchain network. The first miner to solve these equations, and in the process validate a block of transactions, receives what's known as a "block reward." For bitcoin, a block reward is paid as a fraction of digital bitcoin.


The private key (comparable to an ATM PIN) is meant to be a guarded secret, and only used to authorize Bitcoin transmissions. Thus, it’s the “private key” that is kept in a Bitcoin wallet. Some safeguards for a Bitcoin wallet include: encrypting the wallet with a strong password and choosing the cold storage option, i.e. storing it offline. In the case of Coinbase, they offer a secure "multisig vault" to host your keys, which you can sign up for. 
Every time a new transaction is initiated, a block is created with the transactions details and broadcast to all the nodes. Every block carries a timestamp, and a reference to the previous block in the chain, to help establish a sequence of events. Once the authenticity of the transaction is established, that block is linked to the previous block, which is linked to the previous block, creating a chain called blockchain. This chain of blocks is replicated across the entire network, and all cryptographically secured which makes it not only challenging, but almost impossible to hack. I say almost impossible because it would take some significant computational power to even attempt something like that. 

After a certain amount of transactions have been verified by a miner, they will receive newly minted bitcoins for their work and thus new bitcoins will be added into circulation, while the number of bitcoins in circulations are now in the multi-millions range, the maximum amount of bitcoins that can ever be created is capped at 21 million. The creation rate is automatically halved approximately every four years as more bitcoins are added into circulation, whilst this system is modeled after gold, mining difficulty is always increasing as hashrate increases and makes finding new bitcoins harder as the number of available bitcoins reaches the 21 million cap.
Public blockchain networks tend to have pretty high standards for security, while private networks might be a little more trusting. But either way, the rules that form the consensus mechanism are what gives blockchain technology its flexibility and power. Anyone, individually, can check the validity of each transaction and come to a conclusion on whether it’s good or not.
Howdy, Welcome to popular Cryptocurrency blog 'CoinSutra'. I'm Harsh Agrawal, a tech enthusiast & Digital nomad from New Delhi, India.I started CoinSutra to help users around the globe to learn about popular Cryptocurrencies.Here at CoinSutra I write about Bitcoin Wallet, Cryptocurrency wallets, Online Privacy & Security, VPN experiences & making money from Crypto.

When you have your wallet, go to a section that says 'Receive Money' or 'Add funds' or something similar. There will usually be a QR-code that has your Bitcoin address encoded in it. Print out the image with the QR-code and place it next to your cash register. Your customers will typically have a Bitcoin app installed on their smartphone where they can enter the value of the purchase in USD or EUR. Their app calculates the corresponding Bitcoin value. It automatically takes the current exchange rate to get the right amount. On your wallet account you can check the confirmation of your incoming payment.

Because of bitcoin's decentralized nature and its trading on online exchanges located in many countries, regulation of bitcoin has been difficult. However, the use of bitcoin can be criminalized, and shutting down exchanges and the peer-to-peer economy in a given country would constitute a de facto ban.[162] The legal status of bitcoin varies substantially from country to country and is still undefined or changing in many of them. Regulations and bans that apply to bitcoin probably extend to similar cryptocurrency systems.[163]

Illiquidity. This is mostly moot due to Bitcoin’s $47 market cap but it still makes users sweat. It’s highly unlikely that Bitcoin’s price would plummet and you’d be unable to take action, but it’s still unsettling.  As more investors invest, however, illiquidity becomes a negligible risk, as there will likely always be a buyer for Bitcoins waiting.
I can see that blockchain has at least one vulnerability. Sure – decentralization and reconciliation with encryption is fine. But the one vulnerability is the interconnecting network. You foul that up and your blockchain paradigm is now vulnerable. Each node could then be compromised so that reconciliation is impossible. Blockchain does not accomodate the vulnerabilities of the infrastructure which it is using.
Before you buy Bitcoin, you need to download a Bitcoin wallet by going to a site like Blockchain.info, or to a mobile app such as Bitcoin Wallet for Android or Blockchain Bitcoin Wallet for iOS, and filling out an online form with basic details. This shouldn't take more than two minutes. (Related reading, see: Basics For Buying And Investing In Bitcoin)
Remember in our lemonade example, how people in town knew that Rishi wasn’t allowed to sell lemonade and that $500 was way too expensive for a drink made from lemon juice, sugar, and water? Those sorts of rules were agreed upon beforehand by every node in the network—they’re a defining feature of the network. If they didn’t exist, then anyone could sell lemonade for however much they wanted.
It’s decentralized and brings power back to the people. Launched just a year after the 2008 financial crises, Bitcoin has attracted many people who see the current financial system as unsustainable. This factor has won the hearts of those who view politicians and government with suspicion. It’s no surprise there is a huge community of ideologists actively building, buying, and working in the cryptocurrency world.
Bitcoin (BTC) is known as the first open-source, peer-to-peer, digital cryptocurrency that was developed and released by a group of unknown independent programmers named Satoshi Nakamoto in 2008. Cryptocoin doesn’t have any centralized server used for its issuing, transactions and storing, as it uses a distributed network public database technology named blockchain, which requires an electronic signature and is supported by a proof-of-work protocol to provide the security and legitimacy of money transactions. The issuing of Bitcoin is done by users with mining capabilities and is limited to 21 million coins. Currently, Bitcoin’s market cap surpasses $138 billion and this is the most popular kind of digital currency. Buying and selling cryptocurrency is available through special Bitcoin exchange platforms or ATMs.
Most exchanges accept bank transfer or credit card payments, and some even accept Paypal payments. They’ll also charge you a transaction fee for every trade you make. You can choose from hundreds of crypto exchanges, but the most popular and reputable exchanges are Bitfinex, Bitstamp, Coinbase, and Coinmama. Here’s a list of more popular crypto exchanges.
Computing power is often bundled together or "pooled" to reduce variance in miner income. Individual mining rigs often have to wait for long periods to confirm a block of transactions and receive payment. In a pool, all participating miners get paid every time a participating server solves a block. This payment depends on the amount of work an individual miner contributed to help find that block.[86]
×