Hello! Do you know what a spy is? They are people who work secretly to find information for their country. Sometimes they need to get information from other countries but they can’t just ask for it, they have to be very sneaky!
Black-bag cryptanalysis is like being a spy but with hidden codes. Some countries use secret codes to keep their information safe. Black-bag cryptanalysis is the process of secretly breaking those codes to read the information.
To do black-bag cryptanalysis, the spy needs some special tools. The first thing they need is a bag, a black one so no one can see what’s inside. They also need some special tools that can help them break the code.
First, they have to go to the place where the information is stored. They can’t just ask for it because the people at the place won’t give it to them. So they have to sneak in secretly. They have to do it quietly and no one should see them.
Once they are in, they have to find the hidden code. The people who put the information in there made the code very difficult to read, so the spy has to think very hard to figure it out. They use special tools to help them, sort of like a special decoder device.
Once they have figured out the code, they can read the information. They take note of what they find and try to remember everything so they can tell their country about it. Then, they put everything back carefully so no one knows they were there.
So, that's an ELI5 explanation of black-bag cryptanalysis. It's like being a spy who has to break a secret code to read hidden information using special tools, in order to help their country.