Hash is a fixed length of data that is obtained by converting certain data.
Since hashing can only calculate data in one direction, once the data has been hashed, it is almost impossible to revert to the original data.
On the other hand, if the original data is altered even by a single character, the result will be completely different from the hashed data, making it impossible to guess the original data. (Irreversibility)
In the case of cryptography, the encrypted data can be restored, but hashes cannot be restored. For this reason, passwords used on various websites are stored in hashed form.
Hashing is used as a security measure to ensure that the operating companies know the user’s password and that the password is not leaked.
Bitcoin and hashing
The function used to obtain a hash value is called a hash function, and is used when matching passwords, speeding up data retrieval, and checking for data tampering.
In bitcoin mining, there is a race to calculate hashes, and the goal is to obtain bitcoins by calculating hashes in the fastest way possible.
For this reason, miners are working to develop machines that can calculate hashes more efficiently and at higher speeds.