Yes, the available API could be used for signing AND verification. And also, as I learned today, MS also offers a non .NET set of APIs for C and C++ developers. "The Windows 7 Packaging feature is a set of COM-based API that provides support for accessing, modifying, and saving packages by using C and C++." - (http://msdn.microsoft.com/en-us/library/dd371623.aspx) (from: http://blogs.msdn.com/b/dmahugh/archive/2011/04/19/libopc-version-0-0-1-released.aspx) Historically, there have been two popular .NET APIs for Open XML development: System.IO.Packaging (which first appeared in .NET 3.0) and the Open XML SDK, released in early 2007. There’s also a COM-based native packaging API available for non-.NET Windows developers. Aside from this, some enthusiasts began working on a open source component for working with OPC container named libopc. They also wrote a LibreOffice extension for working with MS formats as an alternative to the LO native support for MS formats. It could turn out an interesting project. (http://www.youtube.com/watch?v=RzUlEVLnz6U&feature=player_embedded#!) Dragan -- View this message in context: http://nabble.documentfoundation.org/Digital-signing-MS-format-documents-tp3331970p3341213.html Sent from the Users mailing list archive at Nabble.com. -- For unsubscribe instructions e-mail to: users+help@global.libreoffice.org Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/users/ All messages sent to this list will be publicly archived and cannot be deleted