I need to create a program which has a bit of a database back end, so I was thinking of creating files of a file format of my own personal design with metadata in there some how which would include things like the password needed to access the file, the key(s) for encryption etc and probably some form of checksum to try and prevent outside data manipulation. The only problem is, I have no idea how to add metadata to a file, how to access it etc. Eventually, I might want to add in formatting and font information aswell, but for now, I'll leave that one out