Blockchain technology is secure due to several key features:

1. Decentralization: The data on a blockchain is stored across a network of computers, making it difficult for a single point of failure or attack to compromise the entire system.

2. Cryptography: Each block on the blockchain is encrypted using cryptographic algorithms, ensuring that the data is secure and tamper-proof.

3. Immutability: Once data is added to a block and added to the blockchain, it cannot be altered or deleted without consensus from the network participants, ensuring the integrity of the data.

4. Consensus mechanisms: Blockchain networks use consensus algorithms to validate transactions and ensure that all nodes on the network agree on the state of the blockchain, preventing fraudulent activities.

5. Transparency: The transparent nature of blockchain technology allows all network participants to view the entire transaction history, promoting trust and accountability.

These features work together to create a secure and trustworthy system that is resistant to hacking, fraud, and unauthorized modifications.
Technologie blockchainu je bezpečná, protože je nezměnitelná, což znamená, že data uložená v ní nelze změnit poté, co jsou zaznamenána; transparentní, což znamená, že všechny zapojené strany mohou zobrazit transakční data; distribuovaná, což znamená, že data nejsou soustředěna na jednom místě; a chráněná, což znamená, že jsou šifrována silnou kryptografií.