What is the main purpose of a hashing function?

The main purpose of a hashing function is to generate a unique identifier for data. Hashing functions take an input (or "message") and produce a fixed-size string of bytes that is typically a digest that is unique to each unique input. This digest is a unique representation of the input data; even a small change in the input will result in a significantly different hash value.

This characteristic makes hashing functions extremely useful for various applications, such as ensuring data integrity, storing passwords securely, and creating digital signatures. In the context of data integrity, when information is sent over a network, a hashing function can create a hash of the original data, which can later be used to verify that the data hasn't changed during transmission.

While encryption and decryption are concerned with securing data to make it unreadable or readable by authorized parties, hashing is not about security in the same way. Encryption transforms data into a format that only specific parties can reverse, whereas hashing is a one-way function meant for verification, not confidentiality. Additionally, while hashing can be involved in signing digital contracts, that process typically also involves encryption and other mechanisms, which are not the primary intent of hashing itself.

Thus, option B accurately captures the primary role of a hashing function in