Hi Chris, > Well, the text file that has the data is about 230 megs > or so if I remember right. I don't need all of it, but > the majority of it. > ... > All of the data needs to be hidden until a portion is > retrieved by a particular location, which would be > accessed using that location's password. I have already > explained that if they want "really really" secure data > they're going to have to probably purchase stuff for that, > so I'm looking at making it as secure as I can with what I > have. As long as your average lab monkey can't hack it > without the proper password and location ID that would > probably suffice.
Assuming each locations data is unique to itself, and not part of a shared resource (like a lookup table) then probably the easiest thing to do is to create directories based on the location and encode each file with a different key. The easiest method would probably be to apply some form of compression on the files (zlib is free for use, see snips below) then apply a cryptographic key to the (renamed) zipped file so as to effect encryption. This would reduce the size from 230mb to something closer to 50mb, assuming you used a rather long key, so you could store other resources on the disk as well (like help files, the adobe reader, word doc reader and other tools that not everyone might have available to them that would be necessary to use the program). There's some sample vb code for using the free info-zip libraries at http://vbaccelerator.com/ Introduction to the freeware Info-ZIP libraries: http://vbaccelerator.com/codelib/zip/zipvb.htm In-process Free-threaded Unzipping and Zipping libraries: http://vbaccelerator.com/codelib/zip/zipthread.htm Zipping files using the free Info-Zip Zip DLL with VB: http://vbaccelerator.com/codelib/zip/zip.htm Unzipping files using the free Info-Zip Unzip DLL with VB: http://vbaccelerator.com/codelib/zip/unzip.htm Note that though each of these *do* have visual interfaces, you don't need to have a visual interface - your program can simply decode the file into memory and use it directly without ever asking the user which file(s) to open and extract from the archive. The info-zip libraries do not have to be registered on the client either, just put the dll next to the exe directly on the cdrom. CAPICOM is a COM interface for using the CryptoAPI, which is a standard windows encryption platform. It also adds the option of having signatures for your data - so you can validate that it really came from your business (if you care). Here's a link to more info: http://msdn.microsoft.com/library/en-us/dnsecure/html/intcapicom.asp And the redistributable: http://www.microsoft.com/downloads/release.asp?ReleaseID=44155 Regards, Shawn K. Hall http://12PointDesign.com/ http://ReliableAnswers.com/ '// ======================================================== Quote me as saying I was misquoted. - Groucho Marx '// ======================================================= Rules : http://ReliableAnswers.com/List/Rules.asp Home : http://groups.yahoo.com/group/vbHelp/ ======================================================= Post : [email protected] Join : [EMAIL PROTECTED] Leave : [EMAIL PROTECTED] '// ======================================================= Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/vbhelp/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
