Password protection can be set for a Microsoft excel, word files. Similarly to make a PowerPoint presentation password protected you can do the following.
1. Click on Office button available on the top left of the PowerPoint
2. Navigate to Save As menu and select PowerPoint presentation available under Save a copy of the document section. The following Save As dialog should appear.
3. Select General Options under under the Tools Drop down. The following General Options dialog will appear.
Using this,File encryption and File Sharing protection can be done for a PowerPoint Presentation.