One-way function

A one-way function is like a special secret where you can easily get the answer from the question, but you can't go backwards to get the question from the answer.

Let's say you have a toy box with a certain lock. Your mom puts her favorite toy in the box and locks it. She tells you that the lock can only be opened with a special key that she has.

Now, you can easily check if one key opens the box or not, but you can't easily find the key just by looking at the lock.

This is how a one-way function works, it's like a secret code that can be easily figured out in one direction, but it's impossible or very hard to figure out in the opposite direction. It's useful because it helps keep important information safe and secure.