The cryptocurrencies are virtual coins. They can be exchanged and operated like any other traditional currency, but they are beyond the control of governments and financial institutions.

There is a large number of cryptocurrency available, all with their own characteristics and applications. Those that have greater market capitalization are - at least for now - a minority, which includes bitcoin, bitcoin cash, ether, litecoin, ripple and dash.

Origin of cryptocurrencies

The origin of cryptocurrencies comes from the Cypherpunk movement, originated in the 80s, which advocates the widespread use of cryptography as a tool for social and political change. In 1990, David Chaun created Digicash, a centralized electronic money system that allowed for more anonymous and secure transactions. In 1997, Adam Black proposed Hashcash, a system based on work proof to limit spam and denial of service (DoS) attacks. In 2009, a person or group of people under the pseudonym Satoshi Nakamoto public Bitcoin, the first fully decentralized cryptocurrency, using a chain of blocks (blockchain in English) with proof of work. Bitcoin uses the SHA-256 algorithm, a cryptographic hash function, as its work proof scheme (Proof-of-Work in English).

Currently, there are hundreds of cryptocurrencies based on Bitcoin, although they incorporate more or less variations with respect to the pioneer. The cryptocurrencies are subdivided into: altcoins, metacoins, appchains or appcoins.

The first alternative cryptocurrency that emerged after Bitcoin was Namecoin. He was born in April 2011. Soon after, in October 2011, Litecoin was born. It differs from Bitcoin in that it uses scrypt as its SHA hash function for work proof, instead of SHA-256. Another prominent cryptocurrency is Peercoin (2012), which was the first to use a proof-of-work / proof-of-stake hybrid (work proof / participation test).

Characteristics
In cryptocurrency systems, the security, integrity and balance of your account statements (accounting) is guaranteed by means of a network of agents (segmented file transfer or multi-source file transfer) that are verified (mistrust) mutually called miners, which are, for the most part, public in general and actively protect the network (the network) by maintaining a high rate of processing of algorithms, in order to have the opportunity to receive a small tip, which is distributed in a random manner.

Breaking the existing security in a cryptocurrency is mathematically possible, but the cost to achieve it would be unacceptably high. For example, an attacker trying to break the Bitcoin work test system would need more computational power than the entire network (swarm) of all the miners in the system, and even then, it would only have a probability of success. 50% (authentication round number), in other words, breaking the security of Bitcoin would require a capacity superior to that of technology companies the size of Google.

The main cryptocurrencies of the momento

Bitcoin

Bitcoin is the leader in the world of cryptocurrencies. It was created in 2009 by Satoshi Nakomo, whose real identity remains unknown until today. This made it the first decentralized digital currency and is now the most popular cryptocurrency in the world. Its value has fluctuated significantly over the years, but its trend is definitely bullish. By mid-November of 2017, it had a market value of more than $ 6600. Bitcoin has become a legitimate payment system and currently has more than 100,000 merchants and sellers who accept it as currency. As of September 2017, the BTC had a market capitalization of more than 77,000 million dollars.

Ethereum (ETH)

Ethereum was developed by a Bitcoin programmer and was launched in 2015. It is a decentralized software platform that allows Smart Contracts and Distributed Applications to be created and executed without control, interference, downtime or fraud. It runs on a cryptographic token specific to the platform known as Ether. At the beginning of September 2017, its market capitalization was almost half that of Bitcoin, reaching 36,000 million dollars. The Ethereum is only accepted by a few points of sale as a payment system.

Bitcoin Cash

Bitcoin Cash was created in August 2017 as a fork or Bitcoin Fork after a Hard Fork or hard fork in the block chain of Bitcoin (Blockchain). This was the result of tensions between those who prioritized Bitcoin for its value as an investment over those who prioritized it for its value as a transaction. Since its launch, its price has risen faster than Bitcoin, with a market capitalization since the beginning of September that exceeds 9800 million dollars.

Ripple (XRP)

Ripple was launched in 2012 after 8 years of development. It differs from Bitcoin in that it is not really a cryptocurrency, but rather a decentralized transaction network verified by consensus. You can verify transactions in just a few seconds, much faster than the cryptocurrency. Neither does it require mining, which reduces the use of computational energy and minimizes network latency. At the beginning of September 2017, the market capitalization of Ripple was close to 9000 million dollars.

Litecoin (LTC)

The number 5 in the list of main cryptocurrencies is Litecoin, with a market capitalization of 3400 million dollars as of September 1, 2017. Litecoin was launched by Charlie Lee, a former Google engineer, in 2011 as a Bitcoin fork. It works almost identical to Bitcoin, although it offers faster transaction confirmation, processing transactions approximately 4 times faster than Bitcoin, due to its faster block generation speed. Litecoin is increasingly accepted as a payment currency by merchants.