Some password protected ZIP files, usually created with a recent WinZip (9.0 or newer), are encrypted using new method, the AES encryption.
Older utilities like unzip on Linux, old WinZip, or pkunzip does not know how to handle that, and usually just abort operation complaining that they does not support compression method 99.
To extract those ZIP files one can use:
- recent WinZip (Windows only, €30, free trial)
- 7z tool (Windows, Linux, Mac OS X & others, free, open source – LGPL)
The 7z can be obtained from the 7z home site, but for Linux should be easily available from the system repository.
yum install p7zip p7zip-plugins
Command line syntax for extracting the archive is:
7z x file.zip
Post Scriptum: this is an import of information that I wrote a while ago. Things might have changed since then.