Which of the following statements describes a one-way hash function?

• A. It can be reversed to find the original data
• B. It produces a fixed-size output
• C. It uses multiple keys for encryption
• D. It is dependent on symmetric key length

Answer: (B)

A one-way hash function is designed to take an input of any size and produce a fixed-size output, which is a unique representation of that input data. This is a fundamental characteristic of hash functions, ensuring that their output is consistently sized regardless of the input size.

The primary purpose of a one-way hash function is to generate a unique digest for given data, which cannot feasibly be reversed to retrieve the original data. This characteristic makes it useful in various security applications, such as data integrity checks and password hashing. The output being of fixed size also allows for efficient storage and transmission of hash values.

In contrast, a one-way hash function does not involve the use of encryption keys, nor is it reliant on symmetric key parameters. Therefore, the aspects related to symmetric key length or the use of multiple keys are unrelated to the fundamental nature of a one-way hash function.