What is another name for Hash?

The correct choice, Message Digest, refers to a type of hash function that processes input data and produces a fixed-size string of characters, which typically appears random. This output, known as a message digest, is a unique representation of the input data.

Hash functions serve various purposes in computer science and information security. They are primarily used for data integrity verification, ensuring that data has not been altered. The properties of a message digest generated by a hash function include being deterministic, meaning the same input will always yield the same output, and exhibiting a pre-image resistance, which makes it computationally infeasible to reverse-engineer the input data from the output.

Additionally, a message digest will greatly differ even with minimal changes to the original data, which makes it useful for validating data integrity in cybersecurity and data storage. This characteristic helps identify any unintended alterations to the data.

The other choices represent different concepts. A checksum is primarily used for error detection in data transmission, while encryption keys serve a different purpose in securing data confidentiality. Data fragments pertain to pieces of data rather than a function producing a unique identifier of the whole input. Therefore, 'Message Digest' is the most suitable term synonymous with hash.