Rubber-hose cryptanalysis is when someone tries to figure out a secret code by using physical force or threats to the person who knows the code. It's like if someone takes away your candy and won't give it back unless you tell them your secret code. In the same way, "hackers" or "attackers" might use rubber hoses, torture, or threats to make someone reveal their password or decrypt information that's supposed to be kept secret. It's not a nice thing to do and it's against the law. We shouldn't use physical force or threaten others to get what we want. It's important to protect our secrets and use strong passwords and encryption to prevent this kind of attack.