Replay attack

Imagine you are playing catch with your friend. You toss a ball to your friend and they catch it. But, instead of throwing the ball back to you, they hold on to it. Later on, when you're not looking, they toss that same ball back to you, pretending it's a new throw.

This is what a replay attack is. In technology terms, it's when someone intercepts information that is being sent wirelessly between two devices, and then later on sends that same information back to try and trick one of the devices into doing something it shouldn't.

For example, let's say you have a computer program that allows you to send sensitive information, like your bank account number, to your bank. To make the transaction more secure, your computer and the bank's computer might have a special code that they use to communicate with each other.

But, if someone is able to intercept that code while it's being sent between the two computers, they could use it to send a fake request to the bank later on, pretending to be you, and asking for money to be transferred to their own account. This is a replay attack.

Just like how you and your friend need to be careful when playing catch, computers need to have security measures in place to prevent replay attacks. With the right security protocols in place, the computers can recognize when a message is being resent and ignore it, just like you would recognize if your friend was trying to cheat in your game of catch.