ELI5: Explain Like I'm 5

Message Authenticator Algorithm

A message authenticator algorithm is like a special code that helps make sure that when you get a message from someone or somewhere, you can be very sure that it really came from the person or place you think it did, and that it hasn't been changed or messed with by anyone else along the way.

It's kind of like when you get a letter in the mail or a package in the mail from someone, and you see that the envelope or the box has a special stamp or seal on it that lets you know that it hasn't been opened or messed with by anyone else since it was sent. That stamp or seal is like the message authenticator algorithm.

The code works by taking the message or the information in the message and using a special mathematical formula to come up with a very unique and specific set of numbers and letters that acts like a kind of digital "fingerprint" for that message. This fingerprint is called a hash.

Then, when the message is sent or when you receive it, the algorithm also creates another fingerprint, or hash, from the message you received. If the two fingerprints match up perfectly, then you can be pretty sure that the message really came from the person or place you think it did and that no one tampered with it.

This type of algorithm is very important in things like online banking or sending secure messages because it helps keep your information safe and makes it so that no one can pretend to be you or trick you into giving away important information.