Fundamentals of Blockchain
What is Blockchain?
Blockchain is essentially a decentralized, distributed database. It can be imagined in two ways:
- As a digital, open ledger where all transactions are recorded chronologically and publicly. Anyone can see the entries, but no one can alter them unnoticed. or
- As a massive, public spreadsheet that exists simultaneously on thousands of computers. Each new "entry" in this spreadsheet is verified by all participants and then stored immutably. These entries are the "blocks" that together form the "chain".
History and Development
The basic ideas of blockchain technology date back to the early 1990s. In 1991, Stuart Haber and W. Scott Stornetta published a paper on cryptographically secured chains of blocks. In 1998, Nick Szabo developed the concept of "Bit Gold", a decentralized digital currency system.
However, the blockchain as we know it today was first introduced in 2008 by a person or group under the pseudonym Satoshi Nakamoto in a whitepaper titled "Bitcoin: A Peer-to-Peer Electronic Cash System". This paper laid the foundation for Bitcoin, the first cryptocurrency, which was launched in 2009.
Since then, the technology has rapidly evolved:
- Generation (2009-2013): Focus on financial transactions, mainly Bitcoin.
- Generation (2013-2015): Introduction of smart contracts with Ethereum, enabling the development of decentralized applications (DApps).
- Generation (2015-present): Development of blockchain platforms with improved scalability, interoperability, and sustainability, such as Cardano, Polkadot, and Solana.
- Future developments: Focus on quantum resistance, improved privacy, and integration with the Internet of Things (IoT).
How does Blockchain work?
The functioning of blockchain can be well compared to a relay race. Each runner (block) passes the baton (data) to the next, but before the next runner can start, all referees (network participants) must confirm that the handover was correct. Once a block has been confirmed and added to the chain, it can no longer be altered without changing all subsequent blocks - a practically impossible task.
Important Terms and Concepts:
- Decentralization: No central authority controls the blockchain.
- Consensus: Network participants must agree before new data is added.
- Cryptography: Secures the data and transactions.
- Immutability: Once stored, data cannot be changed.
- Transparency: All transactions are publicly visible.
In contrast, a traditional banking system (TradFi) stands: A central authority (the bank) controls all transactions and data. In blockchain, there is no such central authority - the network itself takes on this role.
These fundamentals form the foundation for understanding blockchain technology. In the following sections, we will delve deeper into specific application areas and more advanced concepts.