Hash

A hash is a unique, fixed-size alphanumeric string that's generated by a mathematical algorithm. Hashes are used to represent data in a condensed, secure form, which is useful for verifying the integrity of data without revealing the original data itself.

In blockchain technology, hashes play an essential role in securing the network. In particular, every block in a blockchain has a unique hash that identifies it and its contents. The hash is generated by applying a hash function to the block's data, which includes the transactions that were recorded in the block, as well as the hash of the previous block in the chain.

By including the hash of the previous block in the hash of the current block, the blockchain creates an immutable ledger that is resistant to tampering. If someone were to change the data in one block, the hash of that block would change, causing all subsequent block hashes to change as well. This makes it virtually impossible to alter data on the blockchain without detection.

Some common hash functions used in blockchain technology include SHA-256 and Scrypt.

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