If you are deep into crypto you must have stumbled upon the word hash, hash rate, or hash power. But what is the meaning of hash in blockchain? And how is it useful for any transaction conducted on a blockchain? Well, a hash is a mathematical computation that converts an input of any length into an encrypted output of a fixed or defined length. Therefore, no matter how long the original information is, the unique hash generated shall always be of the same size.
Hashes are special as they cannot be reverse engineered. This implies that the hashed output cannot be used to find the input since hashes are always one-way. The hash generated from a particular data is always the same but it changes even if a single symbol is modified. A data can be validated if its hash is already known. This hash is the function that helps a blockchain reach its encryption demands. If someone tries to crack the blockchain, it would get extremely difficult for him or her to guess the length of the hash. Therefore, hashes are generally of fixed length.
The hash is developed on the basis of the information present in the block header. Just like a nonce, it behaves as the backbone of the blockchain network. A cryptographic hash function often combines the message-passing capabilities of a hash function with that of its security properties. This increases the security of the hash functions making them more difficult to detect the contents of the message or data.