Bitcoin and other crypto currencies have been gaining in interest in recent years. They are interesting and lucrative investments, which attract more and more interested parties. At the same time, the employment of the digital currencies is extremely exciting. Many users consider them to be the first manifestations of a crypto-economy, which has a revolutionary potential for the way we live and shape economic relations, which we now only have a rough look at.

crypto currencies are a digital currency created by the performance of decentralized computers on the Internet. Unlike conventional money, crypto currencies payments are not issued by banknotes or other trustworthy institutions. The creation of digital coins and transactions - the sending and receiving of payments in a crypto currencies - are without "trustworthy middle-men".

The network participants or the connected computers interact on a peer-to-peer basis, ie on equal footing and at eye level. Mathematical algorithms specify the rules for all activities within the network and can only be changed by the consensus of all network participants. At the same time, they enable a clear assignment of the digital values ​​to specific transmitters and receivers. Data transmission within the network takes place in encrypted form using cryptographic procedures.

The historical roots of cryptanalysis lie in the beginnings of the Internet, with which also questions of data protection in the virtual world on the agenda carry on the agenda. The so-called Cyberpunks, a group of Internet and data protection activists, were already working on cryptographic technologies for the Internet in the early 1990s. Their aim was, among other things, to develop a digital currency that offered the same degree of anonymity as cash payments. However, the development of such a crypt diet failed for more than a decade to ensure that there was no technical solution for the so-called double spending - the double edition of digital coins or double payment instructions - so that a central server could not be abandoned for the time being. This problem was solved first by Satoshi Nakamoto with the blockchain technology and the bitcoin protocol. Bitcoin was thus the first real decentralized crypt diet.

Although the Bitcoin has by far the largest market name among the crypto currencies, many other cryptic diseases have since emerged. Like Bitcoin, they are based on the blockchain technology, but they develop further in detail or on a larger scale. Some of the newer crypto currencies  are a component of more complex ecosystems aimed at establishing digital business models that exceed the framework of financial transactions.

What is the blockchain?

The blockchain is the heart of bitcoin and other digital currencies. It consists of an unbroken chain ("chain") of chronologically successive data blocks, in which all transactions within the network are stored. They are connected by algorithmic strings - the so-called hashes.

In each new data block, a hash of the previous block is included. The data blocks are generated during processing and confirmation of transactions in the digital currency. This procedure is also the basis for the mining (mining) of new coins, if the data protocol of the respective crypto currency as analogous to Bitcoin provides this form of money generation.

The blockchain fulfills the task of a "main book" for the network. However, this database is not stored on a central server, but is located on a variety of computers with full network access and actively support the network with their computing power.

Such computers act as so-called nodes, which can be equipped with different functional scope and task profiles. The intervals in which new data blocks are stored in the blockchain are based on mathematical algorithms and determine the time until confirmation of a transaction. In the Bitcoin network, another data block is created every ten minutes, while other digital currencies sometimes work at significantly shorter intervals.

In addition, the blockchain guarantees the security of the entire network: tampering with the blockchain is impossible, because the hash reference between the individual data blocks would require a back-calculation of all transactions that have been carried out so far. De Blockchain technology is now also of interest to established banks and other companies.