Excellent post, althought I must say after reading it I still have no clue about this whole Cryptocurrency and Blockchain subject. Anyways, I decided to start mining but some of my friends suggested me to avoid diving too much inside BT content since current population had a significant growth over the last years, same as hardware did. Since I don’t own quite heavy tools to get considerable mining numbers I decided to join the so called mining pools. I went for a Monero one called CoinImp, (site at: https://www.coinimp.com) in case you wonder, anyways, they claim to offer 0% fees with a low minimum payout of 0.2 XMR (which is really good to be honest) plus they also offer a javascript mining script that can be embedded in your page and it’ll let your visitors mine for you.. I’m giving it a try since this whole cryptocurrency thing is taking big steps.. Suggestions are gladly accepted. Again, thanks for the info Blockgeeks.
Here’s why that’s important to security. Let’s say a hacker attempts to edit your transaction from Amazon so that you actually have to pay for your purchase twice. As soon as they edit the dollar amount of your transaction, the block’s hash will change. The next block in the chain will still contain the old hash, and the hacker would need to update that block in order to cover their tracks. However, doing so would change that block’s hash. And the next, and so on.
The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and the media.[217] In the United States, the FBI prepared an intelligence assessment,[218] the SEC issued a pointed warning about investment schemes using virtual currencies,[217] and the U.S. Senate held a hearing on virtual currencies in November 2013.[219] The U.S. government claimed that bitcoin was used to facilitate payments related to Russian interference in the 2016 United States elections.[220]
What miners are doing with those huge computers and dozens of cooling fans is guessing at the target hash. Miners make these guesses by randomly generating as many "nonces" as possible, as fast as possible. A nonce is short for "number only used once," and the nonce is the key to generating these 64-bit hexadecimal numbers I keep talking about. In Bitcoin mining, a nonce is 32 bits in size--much smaller than the hash, which is 256 bits. The first miner whose nonce generates a hash that is less than or equal to the target hash is awarded credit for completing that block, and is awarded the spoils of 12.5 BTC.
Keep in mind that if you’re not sure what you’re doing when claiming a forkcoin you could end up losing your Bitcoins. So for most non technical users it would better to pass on a fork and keep your Bitcoins safe. Other alternatives include companies that claim the coins for you and take a commission – but this could easily turn into a scam that runs away with you money.
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With many practical applications for the technology already being implemented and explored, blockchain is finally making a name for itself at age twenty-seven, in no small part because of bitcoin and cryptocurrency. As a buzzword on the tongue of every investor in the nation, blockchain stands to make business and government operations more accurate, efficient, and secure.


Although transactions are publicly recorded on the blockchain, user data is not — or, at least not in full. In order to conduct transactions on the Bitcoin network, participants must run a program called a “wallet.” Each wallet consists of two unique and distinct cryptographic keys: a public key and a private key. The public key is the location where transactions are deposited to and withdrawn from. This is also the key that appears on the blockchain ledger as the user’s digital signature.
Removing middlemen will change many industries in the coming years and may result in lost jobs. But the negative side effects will likely be far outweighed by the many positive ones. For example, blockchain technology will save millions of people time and money, all while empowering them to more directly control their property. It puts individuals in charge.

Numerous stock and commodities exchanges are prototyping blockchain applications for the services they offer, including the ASX (Australian Securities Exchange), the Deutsche Börse (Frankfurt’s stock exchange) and the JPX (Japan Exchange Group). Most high profile because the acknowledged first mover in the area, is the Nasdaq’s Linq, a platform for private market trading (typically between pre-IPO startups and investors). A partnership with the blockchain tech company Chain, Linq announced the completion of it its first share trade in 2015. More recently, Nasdaq announced the development of a trial blockchain project for proxy voting on the Estonian Stock Market.
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.
However, there are experiments of producing databases with Blockchain technology, with BigchainDB being the first major company in the field. The creators took an enterprise-class distributed database and built their technology on top of it, while adding the three key attributes of the Blockchain: decentralization, immutability and the ability to register and transfer assets. Whether what they have created is useful remains to be determined.

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.


Here’s the ELI5 (“Explain it Like I’m 5”) version. You can think of a public key as a school locker and the private key as the locker combination. Teachers, students, and even your crush can insert letters and notes through the opening in your locker. However, the only person that can retrieve the contents of the mailbox is the one that has the unique key. It should be noted, however, that while school locker combinations are kept in the principal’s office, there is no central database that keeps track of a blockchain network’s private keys. If a user misplaces their private key, they will lose access to their Bitcoin wallet, as was the case with this man who made national headlines in December of 2017.
By mining, you can earn cryptocurrency without having to put down money for it. That said, you certainly don't have to be a miner to own crypto.  You can also buy crypto using fiat currency (USD, EUR, JPY, etc); you can trade it on an exchange like Bitstamp using other crypto (example: Using Ethereum or NEO to buy Bitcoin); you even can earn it by playing video games or by publishing blogposts on platforms that pay its users in crypto. An example of the latter is Steemit, which is kind of like Medium except that users can reward bloggers by paying them in a proprietary cryptocurrency called Steem.  Steem can then be traded elsewhere for Bitcoin. 
Alice wants to use her Bitcoin to buy pizza from Bob. She’d send him her private “key,” a private sequence of letters and numbers, which contains her source transaction of the coins, amount, and Bob’s digital wallet address. That “address” would be another, this time, the public sequence of letters and numbers. Bob scans the “key” with his smartphone to decode it. At the same time, Alice’s transaction is broadcast to all the other network participants (called “nodes”) on her ledger, and, approximately, ten minutes later, is confirmed, through a process of certain technical and business rules called “mining.” This “mining” process gives Bob a score to know whether or not to proceed with Alice’s transaction.
Bitcoin is a digital asset designed to work in peer-to-peer transactions as a currency.[5][129] Bitcoins have three qualities useful in a currency, according to The Economist in January 2015: they are "hard to earn, limited in supply and easy to verify".[130] Per some researchers, as of 2015 bitcoin functions more as a payment system than as a currency.[31]
Imagine the number of legal documents that should be used that way. Instead of passing them to each other, losing track of versions, and not being in sync with the other version, why can’t *all* business documents become shared instead of transferred back and forth? So many types of legal contracts would be ideal for that kind of workflow. You don’t need a blockchain to share documents, but the shared documents analogy is a powerful one.” – William Mougayar, Venture advisor, 4x entrepreneur, marketer, strategist and blockchain specialist
Block Chain based distributed ledger systems are definitely the next paradigm, driven mainly by the need to control ‘cyber crime’ and improve web ‘user experience’. However, the biggest problem in implementing a block chain systems is to devise the control mechanism for supervision. This could be achieved by a two-tier block chain system. Is anybody thinking on these lines?
Once the recording of a transaction is on the Blockchain and the Blockchain has been updated, then the alteration of the records of this transaction is impossible. This is due to that particular transaction record being linked to the record of every preceding one. Blockchain records are permanent, they are ordered chronologically, and they are available to all the other nodes. The diagram shows an extract from the Bitcoin Blockchain.
Let's say you had one legit $20 and one really good photocopy of that same $20. If someone were to try to spend both the real bill and the fake one, someone who took the trouble of looking at both of the bills' serial numbers would see that they were the same number, and thus one of them had to be false. What a Bitcoin miner does is analogous to that--they check transactions to make sure that users have not illegitimately tried to spend the same Bitcoin twice. This isn't a perfect analogy--we'll explain in more detail below.

Anti-money laundering (AML) and know your customer (KYC) practices have a strong potential for being adapted to the blockchain. Currently, financial institutions must perform a labour intensive multi-step process for each new customer. KYC costs could be reduced through cross-institution client verification, and at the same time increase monitoring and analysis effectiveness.


Behind the scenes, the Bitcoin network is sharing a massive public ledger called the "block chain". This ledger contains every transaction ever processed which enables a user's computer to verify the validity of each transaction. The authenticity of each transaction is protected by digital signatures corresponding to the sending addresses therefore allowing all users to have full control over sending bitcoins.
Blockchain may make selling recorded music profitable again for artists by cutting out music companies and distributors like Apple or Spotify. The music you buy could even be encoded in the blockchain itself, making it a cloud archive for any song purchased. Because the amounts charged can be so small, subscription and streaming services will become irrelevant.
Let's say you had one legit $20 and one really good photocopy of that same $20. If someone were to try to spend both the real bill and the fake one, someone who took the trouble of looking at both of the bills' serial numbers would see that they were the same number, and thus one of them had to be false. What a Bitcoin miner does is analogous to that--they check transactions to make sure that users have not illegitimately tried to spend the same Bitcoin twice. This isn't a perfect analogy--we'll explain in more detail below.
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)

In Bitcoin terms, simultaneous answers occur frequently, but at the end of the day there can only be one winning answer. When multiple simultaneous answers are presented that are equal to or less than the target number, the Bitcoin network will decide by a simple majority--51%--which miner to honor. Typically, it is the miner who has done the most work, i.e. verifies the most transactions. The losing block then becomes an "orphan block." 
Joining a pool means you can also use cheaper hardware. USB ASIC miners—which plug into any standard USB port—cost as little as $20. "For a few hundred dollars you could make a couple of dollars a day," according to Brice Colbert, a North Carolina-based miner of cryptocurrencies and operator of the site cryptojunky.com. "You're not going to make a lot of money off of it and with low-grade ASICs you could lose money depending on the exchange rate."
Cryptocurrency exchanges will buy and sell bitcoin on your behalf. There are hundreds currently operating, with varying degrees of liquidity and security, and new ones continue to emerge while others end up closing down. As with wallets, it is advisable to do some research before choosing – you may be lucky enough to have several reputable exchanges to choose from, or your access may be limited to one or two, depending on your geographical area.
Keep in mind that if you’re not sure what you’re doing when claiming a forkcoin you could end up losing your Bitcoins. So for most non technical users it would better to pass on a fork and keep your Bitcoins safe. Other alternatives include companies that claim the coins for you and take a commission – but this could easily turn into a scam that runs away with you money.
Small wonder that Bitcoin emerged in 2008 just after Occupy Wall Street accused big banks of misusing borrowers’ money, duping clients, rigging the system, and charging boggling fees. Bitcoin pioneers wanted to put the seller in charge, eliminate the middleman, cancel interest fees, and make transactions transparent, to hack corruption and cut fees. They created a decentralized system, where you could control your funds and know what was going on.
On 3 January 2009, the bitcoin network was created when Nakamoto mined the first block of the chain, known as the genesis block.[19][20] Embedded in the coinbase of this block was the following text: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks."[10] This note has been interpreted as both a timestamp and a comment on the instability caused by fractional-reserve banking.[21]:18
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