What is cryptocurrency?

A cryptocurrency is a digital or virtual currency designed to work as a medium of exchange. It uses cryptography to secure and verify transactions as well as to control the creation of new units of a particular cryptocurrency. Essentially, cryptocurrencies are limited entries in a database that no one can change unless specific conditions are fulfilled.

History
In the early 2009, an anonymous programmer or a group of programmers under an alias Satoshi Nakamoto introduced Bitcoin. Satoshi described it as a ‘peer-to-peer electronic cash system.’ It is completely decentralized, meaning there are no servers involved and no central controlling authority. The concept closely resembles peer-to-peer networks for file sharing.

One of the most important problems that any payment network has to solve is double-spending. It is a fraudulent technique of spending the same amount twice. The traditional solution was a trusted third party - a central server - that kept records of the balances and transactions. However, this method always entailed an authority basically in control of your funds and with all your personal details on hand.

In a decentralized network like Bitcoin, every single participant needs to do this job. This is done via the Blockchain - a public ledger of all transaction that ever happened within the network, available to everyone. Therefore, everyone in the network can see every account’s balance.

Every transaction is a file that consists of the sender’s and recipient’s public keys (wallet addresses) and the amount of coins transferred. The transaction also needs to be signed off by the sender with their private key. All of this is just basic cryptography. Eventually, the transaction is broadcasted in the network, but it needs to be confirmed first.

Within a cryptocurrency network, only miners can confirm transactions by solving a cryptographic puzzle. They take transactions, mark them as legitimate and spread them across the network. Afterwards, every node of the network adds it to its database. Once the transaction is confirmed it becomes unforgeable and irreversible and a miner receives a reward, plus the transaction fees.

Essentially, any cryptocurrency network is based on the absolute consensus of all the participants regarding the legitimacy of balances and transactions. If nodes of the network disagree on a single balance, the system would basically break. However, there are a lot of rules pre-built and programmed into the network that prevents this from happening.

Cryptocurrencies are so called because the consensus-keeping process is ensured with strong cryptography. This, along with aforementioned factors, makes third parties and blind trust as a concept completely redundant.

Many people believe that cryptocurrencies are the hottest investment opportunity currently available. Indeed, there are many stories of people becoming millionaires through their Bitcoin investments. Bitcoin is the most recognizable digital currency to date, and just two years ago one BTC was valued at $400. In December 2017, the price of one Bitcoin exceeded $19,000.

Ethereum, perhaps the second most valued cryptocurrency, has recorded the fastest rise a digital currency ever demonstrated. Since May 2016, its value increased by at least 2,700 percent. When it comes to all cryptocurrencies combined, their market cap soared by more than 10,000 percent since mid-2013.

If you decide to invest in cryptocurrencies, Bitcoin is obviously still the dominant one. However, in 2017 its share in the crypto-market has quite dramatically fallen from 90 percent to just 40 percent. There are many options currently available, with some coins being privacy-focused, others being less open and decentralized than Bitcoin and some just outright copying it.

While it’s very easy to buy Bitcoins - there are numerous exchanges in existence that trade in BTC - other cryptocurrencies aren’t as easy to acquire. Although, this situation has improving rapidly with major exchanges like Coinbase, Kraken, Bittrex, Poloniex and many others starting to sell Litecoin, Ethereum, Monero, Ripple and so on.