Shred a deleted file

[taw]

I have a text output file (with bank account info) that gets built from a table then uploaded to the bank. After this, I have a function for the user to delete the output file. Is there a way to make sure that the output data is no longer recoverable from the hard drive? Would it be enough to rewrite the records with random gargbage before deleting the file?

Thanks for your input.

Tom