Was ist eine Blockchain?

A decentralized, digital ledger in which the exchange of value is recorded chronologically and publicly.

Blockchain technology as we know it today was first outlined by anonymous author Satoshi Nakamoto in the Bitcoin white paper . As Nakamoto outlined, transactions issued in Bitcoin are verified by cryptography and recorded in a publicly distributed ledger.

Banking or accounting systems may contain a copy of a ledger that represents the flow of financial transactions through one’s account. In principle, account holders trust individuals or organizations to maintain the integrity of a ledger and verify both incoming and outgoing transactions. As such, ordinary ledgers are not immutable – they are vulnerable to accidental or deliberate tampering, whether by error or intent.

Blockchain technology solves this problem by doing away with the need for a “middleman” and instead broadcasting a public ledger on computers – “nodes” – around the world. While one could rely on the trustworthiness of a bank to authenticate the integrity of a ledger, blockchain technology instead relies on cryptography (the art of writing or solving codes) as its proof.

What is blockchain technology?

Blockchain technology takes its name from the underlying data structure, which consists of 1-megabyte files called “blocks,” which are essentially ledgers themselves. Blocks are “chained” together by a complex cryptographic proof that ensures permanence; like a fly encased in layers of amber, transactions are confirmed over and over again over time. If one party were to attempt to edit a historical transaction, all transactions afterward would immediately show the error.

In an “open” system, all network nodes have the ability to access a blockchain and view authenticated transactions.

This means that computers around the world each have a copy of this public ledger, and transactions carried out on a network are visible to everyone. The parties to the transaction are pseudonymized because a blockchain does not illustrate the names of the parties, but instead provides an alphanumeric designation.

What is a “proof of employment”?

The process of authenticating pending transactions and aggregating them into a block for inclusion in a blockchain is called “proof-of-work” or “mining.” “Miners” are computer users with incredibly powerful hardware who solve complex mathematical problems to cryptographically sign a block of transactions and connect them to all previous transactions on a network.

Miners serve cryptocurrency communities by securing a network. The process of solving the cryptographic proof of a block is extremely resource-intensive; by winning the race to mine 1-megabyte “blocks” of transactions, miners receive a “bounty” or “reward” in a corresponding cryptocurrency.

A malicious transaction requires so much computing power (and therefore electricity) that in almost all cases it is more profitable to instead use that same computing power to secure the network and collect the block reward. This prevents malicious actors from attacking the network and prevents the blockchain from recording malicious or fraudulent inputs.

What is “proof of fraud”?

Newer cryptocurrencies have instead developed a new mechanism called “proof-of-stake,” which transforms the process of resource-intensive “mining” into one in which coin owners receive network resources and authority in proportion to the coin holdings they are willing to “stake” on a network.

While Proof-of-Work mining uses processing power to solve increasingly difficult puzzles, Proof-of-Stake verification attributes mining power primarily to the proportion of coins a miner owns.

The method gets its name from the fact that in this scenario, a miner is limited to mining a percentage of transactions that correlates with his or her “ownership” share of a network.

Through one of these mechanics – or a mix of both – users around the world can help run a blockchain. Despite the likelihood that these users are acting out of self-interest (to receive a reward in the form of a cryptocurrency), their actions are inherently beneficial to a blockchain network, not destructive.

How does a blockchain manage transactions?

When transacting on a blockchain, parties use what is called a “wallet” to exchange denominations of a cryptocurrency. Wallets provide their users with both a public key (the address from which one sends or receives cryptocurrency) and a private key.

A private key is a “signature” for users that serves to confirm pending transactions by providing mathematical proof that they originated from the owner of the wallet in question.

When a user wishes to make a transaction, their intent is signaled on a blockchain by submitting a transaction signed with the user’s private key. A network then validates the transaction by checking that the arrival and departure addresses are valid, that the private key is valid, and that it has access to enough funds to make the transaction. The transaction is typically confirmed on the network within minutes and then broadcast to a blockchain network within a “block.”

What is a “public” blockchain?

A public blockchain has no access restrictions, meaning that anyone with an internet connection would be able to make a transaction while running relevant software or become a validator in the first instance on such a network. The Bitcoin network is the first example of a public blockchain.

What is a “private” blockchain?

Private blockchains, on the other hand, are “permissioned” – meaning that new users cannot automatically join a network as participants or validators unless they are invited by a network administrator. Such networks are typically used by companies that want to integrate blockchain technology into their accounting or auditing practices without releasing sensitive financial data to the public.

Can a blockchain only be used to track funds?

While blockchain technology may have a natural use for managing a new form of digital currency like Bitcoin, blockchains do not have to be limited to managing currency exchanges per se.

Blockchain technology, as a distributed digital ledger, is able to manage the transfer of assets. Of course, beyond managing a currency, this can extend to physical and digital properties – blockchain technology could allow users around the world to record their ownership of items such as real estate, digital media, or even materials in a supply chain.

In some cases, blockchain technology has found a home in counting government elections, managing social networks, or managing distributed data storage or computer processing networks.