Yes, you can do this. You will need a SlideShare PRO account for private sharing. Using that, you can disable the download of the file, so that the viewer can only read/view the presentation, but not be able to download it. 

To learn how to disable downloads, follow the steps below:

• Login to SlideShare
• Go to the drop down menu on the top right of every page and select  My Uploads
• Go to the Edit link of the presentation you want to disable the download for
• Un-check the Allow viewers to download file option
• Click the Update button at the bottom of the page