About Hashing

Hashing is a process of taking an input (often called a message), and producing a fixed-sized output (often called a hash or digest) that is a representation of the input data. The hash is generated using a mathematical function that transforms the input into a unique string of characters, making it extremely difficult to reverse the process and determine the original message from the hash.

The hash functions are designed in such a way that even a small change in the input will result in a completely different hash, this property is known as the "avalanche effect". This makes it very difficult for attackers to manipulate the input data without being detected, as the resulting hash would be completely different from the expected value.

For example, in the case of password authentication, instead of storing the user's password in plain text, the password is hashed and the hash value is stored in the database. When the user attempts to log in, the system hashes the entered password and compares the hash with the value stored in the database. If the hashes match, the user is granted access. This approach ensures that the passwords are stored securely and are not accessible even if the database is compromised.