Wiki
Clone wikiAspose Java for Docx4j / Apply-Password-Protection
Aspose.Slides
//Instantiate a Presentation object that represents a PPT file Presentation pres = new Presentation(); //Setting Password pres.getProtectionManager().encrypt("pass"); //Save your presentation to a file pres.save("data/AsposeProtection.pptx", com.aspose.slides.SaveFormat.Pptx);
Download Source Code
For More Examples, Please Visit Aspose Docs
Updated