When someone hands you a password-protected ZIP archive, one’s immediate thought is “I need to break the password”. For most modern archives, that is exactly the case, and the password is the whole game. But there is a family of ZIP archives where the password does not matter at all. It can be four characters or forty, random or memorable; if the archive uses the legacy ZIP encryption, the whole thing can be unlocked in minutes without ever guessing the password. This is one of the oldest tricks in our line of work, and it is worth telling the story properly, because it is equal parts computer history and practical forensics.

The recent update to Elcomsoft Advanced Archive Password Recovery, our go-to tool for breaking passwords to encrypted archives, brought compatibility with RAR5 and 7Zip formats, and enabled multithreaded dictionary attacks. Which archive formats are the most secure, and which ones are the toughest to break? Read along to find out!