Читать книгу Blockchain Data Analytics For Dummies - Michael G. Solomon - Страница 35

Blockchain technology is based on the concept of linking blocks together using a cryptographic hash. A cryptographic hash function takes any characters as input and creates a fixed-length output that represents the input. Calculating a hash value is easy, but finding the original input from the hash is extremely difficult. If the input changes at all, the hash function will calculate a different hash value.

Blockchain nodes calculate the hash value of a block and store that value in the next block on the chain. That process links the blocks and also detects changes in blocks. If any data in any block gets changed, the hash value of the block changes and makes the next block’s link (remember it was the original block’s hash value) invalid. Any change breaks the chain.