Editing sensitive data
======================

If you temporarily decrypt your data in order to edit certain files, you
should not simply save the edited files over the original ones in your Data
directory if you are seriously concerned about the security of the data. If
an edited file is shorter than the original one, and if you 'overwrite' the
original version with the new one, some of the old data may remain on the
disc even after all traces of the new files are securely wiped from the disc
when using !Erase.

In order to guarantee that no traces of the original data remain after
re-encryption, the following procedure is recommended:

1. Before editing any file in your Data directory, first *move* it to the
directory 'scrap' inside !Erase. (Do *not* 'copy' it there and then 'delete'
the original file!)

2. After editing the file, save a copy of it once again in your Data
directory.

3. Double-click on the application !Erase. After asking for confirmation,
this utility destroys all traces of everything in the directory 'scrap'. For
extremely sensitive information, !Erase enables you to destroy the data with
a higher level of security than its default. Read the !Help file inside
!Erase for instructions on how to do this.

4. Double-click on !Store to re-encrypt your data. The copy in Data will be
securely wiped from the disc.

If you want to save a file several times during the editing process, simply
repeat steps 1-3 as many times as necessary.


Other precautions
=================

To ensure the absolute security of your data, you must guard against any
operations which 'delete' files or create extra copies. For example, you
should disable any utility which periodically performs automatic 'autosave'
operations.

If sensitive files are to be moved between different discs or filing
systems, you can first copy them and then destroy the copy in the original
location by means of !Erase.  To do this, you will need a copy of !Erase on
the appropriate disc or filing system, so that you can safely 'move' the
files into the directory 'scrap' in order to destroy them.

Even if such precautions are taken, it is best to prevent any unauthorised
access to your computer. A serious hacker could, for example, install a
hidden program which captures your passphrase whenever you use !Stealth, or
which records all keystrokes.