What does a hashing algorithm do?

A hashing algorithm is designed to take input data, regardless of its original size, and transform it into a fixed-size string of characters, which is commonly referred to as a hash value or digest. This hash value is unique to the input data and serves several purposes, including verifying data integrity and checking passwords. The fixed size of the output helps standardize the representation of data, making it easier to manage and compare.

The correct answer highlights this fundamental purpose of a hashing algorithm. Unlike encryption, which secures data by making it unreadable without a key, hashing does not allow for the original input data to be retrieved from the hash value. It focuses on creating a concise representation of the data that can be easily stored or transmitted, while still allowing for verification processes, such as comparing hash values to confirm if two sets of data are unchanged.

The other options do not accurately describe the primary function of a hashing algorithm. Storing data in an encrypted format pertains to encryption methods, compressing data refers to reducing the size of data for quicker transmission, and providing a means of data backup involves techniques for saving data securely, none of which align with the fundamental characteristics of a hashing algorithm.