Since the early times of mankind, we've been trying to make an unbreakable form of encryption to keep information safe.
This is known as the study of cryptography, and it's where you try to make information encrypted so that only the people you want will be able to decode a coded message.
In a coded message, something that makes absolutely no sense to one person can be translated to something understandable with a key. This is common in computers, but the military, police forces, and other secretive organizations also use encryption to keep information safe.
There are so many ways to encrypt information that they can't be counted on your fingertips, but chances are, there will never be a way to encrypt something in a way that can't be decrypted, given people actually have the time to break the code.