[Ubuntu]Preventing recovery of deleted files
Here below is a simple method, on how preventing the recovery of deleted files:
- First, make sure the recycle bin of Nautilus (the file browser) is empty.
- Right click on it and choose the option Empty Recylcle bin
Note that: If you have other partitions (FAT, NTFS ...), each of them has its own recycle bin and this manipulation will not be applicable tothem
To view these hidden files press (CTRL + H) and look at the root of each partition the directory for the
.Trash ou .
Trash-nameofpartition folders and delete the files.
Crushing the free space
To avoid the recovery of deleted files, use the secure-delete package .
Installation: sudo aptitude install secure-delete
Command:
sudo sfill -l -l -v /
For a more effective results use the command:
sudo sfill -v /
Note:
- For certain file systems (such as ext3), it is impossible to guarantee a permanent deletion.
- Programs are included with secure-delete: srm (deleting a file), smem (erasing the memory), sswap (erasing the swap file).
- For a file to be never written unencrypted disk, you can use encrypted file systems like TrueCrypt.
http://en.kioskea.net/telecharger/telecharger-113-truecrypt 
Bash delete files in a list