Differential cryptanalysis is like a puzzle where you have to figure out the secret code used to keep a message safe because you don't have the key to unlock it.
Imagine you have two secret messages, one that you know and one that you want to figure out. They are both encoded using a similar but different secret code. You notice that when you change one letter in the first message, some of the letters in the second message also change.
This is like a "difference" between the two messages. By making small changes and observing the differences between the two messages, you can start to figure out how the code works.
Differential cryptanalysis is a way of using these differences to guess the secret code used to encrypt the message. With enough guesses and observations, you can eventually crack the code and read the secret message.
It's like trying to solve a really tricky puzzle, but instead of matching colors or shapes, you're looking for patterns and differences between secret messages.