A blockchain is a decentralized database. It is distributed on a network of thousands of servers.
A new entry has to be verified by the majority of them. After this, all servers of the network update their version of the database. When one block is complete, the next one is generated. Due to the chronological storage of data in the individual blocks of the chain, these cannot be changed subsequently without damaging the entire system. The data on the blockchain is encrypted and manipulation is largely restricted. You can see that a transaction took place, but no private information is published. The blockchain is accessible to everyone worldwide. It became well-known as the technology behind the digital currency Bitcoin.
Sheila Warren is the World Economic Forum's head of blockchain and distributed ledger technology, the tech which makes cryptocurrencies such as Bitcoin possible. Speaking to DW at the WEF annual meeting at Davos, she explained why she feels Bitcoin — whether it is here to stay or not — will always be known as a trailblazer.
The head executive of Exmo Bitcoin exchange Pavel Lerner has reportedly been kidnapped on the streets of Kyiv. His company, which focuses on trading cryptocurrencies in east Europe, says it is still operating normally.