Base

Is blockchain secure?

   Once a block is added to the end of the blockchain, it is very difficult to go back and change the content of the block.    Because each block contains its own hash and the hash of the block before it.    Hash codes are created by a mathematical function (hash function).

Lingo

Furthermore, the decentralized and distributed nature of blockchain networks adds another layer of security. In a decentralized blockchain network, multiple nodes (computers) maintain copies of the blockchain and participate in the process of validating and adding new blocks.