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Opening Password Protected PPT Files


Previously, the topic of opening password protected ppt files has been discussed. Mostly, this was related to the Microsoft PowerPoint Viewer being able to display password protected files.

However, what was never discussed was allowing ASPose.Slides to read the ppt file if the password was supplied. I think this option would be much more doable than trying to reverse engineer what the Microsoft PowerPoint Viewer is doing.

This is an important issue for me.

Please let me know your thoughts.

Kind Regards,


Hello Alex,

There is only one problem with opening password protected files.
MS Office uses RC4+MD5 for crypting files but the problem is Word, Excel, PowerPoint and
other office apps do additional data manipulations. For example Word crypts documents page by page
and uses number of page as addon for password. Excel uses absolutely different algorithm.
Unfortunately we don’t have any information about PowerPoint’s algorithm.