Saving encrypted customProperties outside the app?

[Robert Hyde]

Hello!

I am working on an app that stores a large amount of information in 
customproperties, since they are easily and logically accessible as well as 
extremely fast.  This information is stored outside the app itself so that 
various data files can be created and so that the app can auto-save the 
user's work every 5/10/20/30 minutes per the user's choice.  Currently I 
accomplish this by copying the current custompropertyset to a substack, then 
clone that substack and save it as a file.  When the user wants to open that 
data, it opens the saved substack clone, copies in the custompropertyset, 
and it is done.

The problem comes in when I want to add security to it, since the user may 
be typing up sensitive data...  Only the user that saved the data should be 
able to open it, even from Rev.  Even when you add a password in the code or 
via the distribution builder, the custompropertyset information is not 
encrypted, just the code itself.  So anyone can open that cloned substack 
within rev and see what is in the custompropertyset, even if they may not 
know exactly how to translate it.  I played with adding a script to 
preOpenStack that asks for a password and checks it against one saved within 
the stack, but in Rev you can just suppress messages and preOpenStack 
doesn't fire, so it leaves the file wide open.

I know that I could just save that data as a substack within the app, and 
the distribution builder would keep that invisible within the .exe, but the 
user needs to be able to save to a separate data file.

I think that I could just save the custompropertyset as its own file, I have 
seen examples of saving arrays to a file, saving just about everything to a 
file, but then there is no way to require a password, so it could be opened 
within Rev, and that does not solve my problem.

So does anyone know of a good way to save custompropertyset information in a 
data file separate from the app itself in such a way that it would require 
something akin to a password to get to it even within Rev?  I may be 
overlooking something painfully obvious, but I just can't think of anything. 
  Is there a way to store that data within a stack that cannot be viewed 
from the properties page?  I really appreciate any suggestions at all.  
Thanks!

Robert

_________________________________________________________________
Add MSN 8 Internet Software to your existing Internet access and enjoy 
patented spam protection and more.  Sign up now!   
http://join.msn.com/?page=dept/byoa