Excel import check Sheet password asp.net EPPLUS : I'm using EPPlus to create excel file with some restriction (lock, validation,..) and i have set a password for the sheet : 
sheet.Protection.IsProtected = true;
sheet.Protection.SetPassword("pass");

Users have to make some changes in the file and import the same file. 

How can i check when importing file that the passwod is the same ("pass") 
using EPPLUS ? i want to be sure that user use and import the same Excel file. 

Thanks a lot for your help.