File Encryption ... File Uploading ...

Hello,

I am planning to provide the Pause/Resume while uploading files.

Our site is using both java applet and activex to do this.

The list of selected files will be stored in an encrypted file using SHA256
(I have taken the code from:
http://www.vbforums.com/showthread.php?s=&threadid=232284)

The user can Pause file uploading and can resume file uploading even without
login to our site at any time (even after days/weeks).

Since the list of files are stored on an encrypted file our site's client
service program will upload the rest of files.

I invite all to discuss about the security issues arise out of this solution
and how secure is the above program using SHA256?

Thank you,

Regards,

Raj.