According to the website HFSExplorer can open and read encrypted dmg images. Meet DMG Extractor, a professional tool to extract the. The encrypted folder is now mounted and you can copy files to it or delete existing files. Click on Open Type the file size to be reducedSelect ResizeDone In Once the file has downloaded, open your Downloads folder, right click on the file, and select extract all from the context menu. It is very similar to ISO files in windows, or rather a counterpart of ISO files.