A cryptocurrency (or crypto currency) is a digital asset designed to work as a medium of exchange that uses cryptography to secure its transactions, to control the creation of additional units, and to verify the transfer of assets.Cryptocurrencies are a type of digital currencies, alternative currencies and virtual currencies. Cryptocurrencies use decentralized control as opposed to centralized electronic money and central banking systems. The decentralized control of each cryptocurrency works through a blockchain, which is a public transaction database, functioning as a distributed ledger.[6] Bitcoin, created in 2009, was the first decentralized cryptocurrency. Since then, numerous other cryptocurrencies have been created.[8] These are frequently called altcoins, as a blend of alternative coin.

Formal definition

According to Jan Lansky, a cryptocurrency is a system that meets all of the following six conditions:

1. The system does not require a central authority, distributed achieve consensus on its state.
2. The system keeps an overview of cryptocurrency units and their ownership.
3. The system defines whether new cryptocurrency units can be created. If new cryptocurrency units can be created, the system defines the circumstances of their origin and how to determine the ownership of these new units.
4. Ownership of cryptocurrency units can be proved exclusively cryptographically.
5. The system allows transactions to be performed in which ownership of the cryptographic units is changed. A transaction statement can only be issued by an entity proving the current ownership of these units.
6. If two different instructions for changing the ownership of the same cryptographic units are simultaneously entered, the system performs at most one of them.

Blockchain - Coinlero

Main article: Blockchain

The validity of each cryptocurrency's coins is provided by a blockchain. A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a hash pointer as a link to a previous block, a timestamp and transaction data.By design, blockchains are inherently resistant to modification of the data. It is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way".For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority.

Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain. It solves the double spending problem without the need of a trusted authority or central server.

The block time is the average time it takes for the network to generate one extra block in the blockchain. Some blockchains create a new block as frequently as every five seconds. By the time of block completion, the included data becomes verifiable. This is practically when the money transaction takes place, so a shorter block time means faster transactions.

What is cryptocurrency and how cryptocurrencies emerged as a side product of digital cash

Few people know, but cryptocurrencies emerged as a side product of another invention. Satoshi Nakamoto, the unknown inventor of Bitcoin, the first and still most important cryptocurrency, never intended to invent a currency.

In his announcement of Bitcoin in late 2008, Satoshi said he developed “A Peer-to-Peer Electronic Cash System.“

His goal was to invent something; many people failed to create before digital cash.

Announcing the first release of Bitcoin, a new electronic cash system that uses a peer-to-peer network to prevent double-spending. It’s completely decentralized with no server or central authority. – Satoshi Nakamoto, 09 January 2009, announcing Bitcoin on SourceForge.

The single most important part of Satoshi‘s invention was that he found a way to build a decentralized digital cash system. In the nineties, there have been many attempts to create digital money, but they all failed.

… after more than a decade of failed Trusted Third Party based systems (Digicash, etc), they see it as a lost cause. I hope they can make the distinction, that this is the first time I know of that we’re trying a non-trust based system. – Satoshi Nakamoto in an E-Mail to Dustin Trammell

After seeing all the centralized attempts fail, Satoshi tried to build a digital cash system without a central entity. Like a Peer-to-Peer network for file sharing.

This decision became the birth of cryptocurrency. They are the missing piece Satoshi found to realize digital cash. The reason why is a bit technical and complex, but if you get it, you‘ll know more about cryptocurrencies than most people do. So, let‘s try to make it as easy as possible:

To realize digital cash you need a payment network with accounts, balances, and transaction. That‘s easy to understand. One major problem every payment network has to solve is to prevent the so-called double spending: to prevent that one entity spends the same amount twice. Usually, this is done by a central server who keeps record about the balances.

In a decentralized network, you don‘t have this server. So you need every single entity of the network to do this job. Every peer in the network needs to have a list with all transactions to check if future transactions are valid or an attempt to double spend.

But how can these entities keep a consensus about this records?

If the peers of the network disagree about only one single, minor balance, everything is broken. They need an absolute consensus. Usually, you take, again, a central authority to declare the correct state of balances. But how can you achieve consensus without a central authority?

Nobody did know until Satoshi emerged out of nowhere. In fact, nobody believed it was even possible.

Satoshi proved it was. His major innovation was to achieve consensus without a central authority. Cryptocurrencies are a part of this solution – the part that made the solution thrilling, fascinating and helped it to roll over the world.

How Does Cryptocurrency Work?

Cryptocurrency is an encrypted, decentralized digital currency transferred between peers and confirmed in a public ledger via a process known as mining.

Below, we take a simplified look at how cryptocurrencies like bitcoin work. First, let’s review the basics and essentials of cryptocurrency, and then we will do an overview of the other properties that have made cryptocurrency what it is today.

TIP: If the page below feels overwhelming, please see: “how does cryptocurrency work (for beginners).” Meanwhile, if you are mainly interested in trading, investing in, or using cryptocurrency, see “how to trade cryptocurrency (for beginners).” This page provides an overview of the mechanics behind cryptocurrency.