RndShred application will create a block of randomized data and writes this block of data over your entire file.
Each pass this block of data is re-randomized to prevent a data recover service from finding ghost versions of your data remaining after deleting a file by just using 1 pass.
Running 3 passes if good for simple usage, but 7+ passes is recommended to
prevent any possible way of recovering the data by testing depths of the write
impressions. There are many articles on the Internet describing how you can
recover data from a disk, even though the file has been physically overwritten
with new data. (Article in PcMagazine - October 1, 2003 - "All Is Not Lost")
RndSred can auto-rename your file to a random filename using the same # of
characters as the original. This will help to prevent someone from knowing
the name of the file.
Check the auto-delete box to delete the file once RndShred is finished.
Default is 8 passes for heavy-duty shredding. 3 Passes is a low setting, and
anything over 8 passes is probably overkill. Yet this depends on your drive
and media type. RndShred is assuming you are shredding files on a hard drive.
You should read up on the media you are trying to shred files on to determine
the best possible # of passes to render your information unrecoverable.