Final answer:
In cryptography, non-reversible operations are known as hash functions, such as SHA-256 and MD5, and they are designed to be computationally infeasible to reverse.
Step-by-step explanation:
In the field of cryptography, non-reversible operations are commonly referred to as hash functions. A hash function takes an input (or 'message') and returns a fixed-size string of bytes. The output is typically a 'digest' that uniquely represents the input data. One key property of hash functions is that they are designed to be one-way functions; that is, they are deliberately difficult to reverse. This means that if you are given the output digest, it should be computationally infeasible to reverse the process and find the original input.
Examples of widely-used hash functions include SHA-256 and MD5, although MD5 is now considered to be weak and vulnerable to collisions. These hash functions are fundamental in various security protocols and systems, such as digital signatures and password hashing, to ensure that the original data cannot be easily uncovered or tampered with.