If there are to be encryption keys for any backup they must be provided to the client and not reside with Miro - this is security 101.
                
     
                                    
            hello my board backup is coming in rbt file type instead of pdf
                
     
                                    
            Hi @Gunja 
 
I replied to your question in the other thread you posted in. Hope you find it helpful!
                
     
                                    
            Hi @Ed Burke 
Not sure if I understand your question fully. If you rename an RTB file to a ZIP file, you should be able to open it and see the images. At least in my case just tested it, still works at least on the board I tried.
As far as CHANGING anything in the file . . . well, checksums and all that. 
Looking for something different?
Cheers, Ken