File Vault...

I want to add a file fault system to my application that allows the user to select a file and then this file is stored within the vault. The only thing is that I need these files to completely secure e.g. the files can not be deleted, renamed or modified by anyone outside of my application. The reason for this is that I have have to be 100% positive that these files have not been tampered with as these will be used to provide audit and legal uses.

I therefore am unable to use standard security accounts within Windows as obviously people can create accounts and modify folder properties.

I am unable to save these files into a database as some of the files maybe as large as 500 Meg. I was therefore need another method to do this, would a private virtual drive be a solution. Howver I know nothing about this and if this file can be password protected?

I know there is a lot of file and folder locking software would there but obviously I need to include this into my app and also I do not know how this software works.

Any advise would be really appreshiated.

I don't think you can do anything with .net . If i am the admin then i can delete your file.Simple.
I have never used locking software so i cannot help you.My advice is to take backup of the vault every day.

You could always open a stream to those files and not close it, until you want to release them from the 'vault'.

vb Code:

'"Lock the file
Dim sw as new io.streamwriter(file)
 
'"Unlock the file
sw.Close()

Not sure if thats a good idea or a very bad one, just the first thing that came me to my mind.

Well the fact is that the files can get deleted once saved.