The Chilkat Zip component can produce WinZip-compatible AES encrypted .zip archives. WinZip added it’s AES encryption capability with version 9.0 of its product. Therefore, if you try to use WinZip 8.0 and under to unzip an AES encrypted Zip, you will get the error: Unsupported Compression Method. This is because the AES Encryption compression method is 99. It will not be recognized by earlier versions of WinZip.