Graphics Programs Reference
In-Depth Information
In our example, we're using a blank user password, which is very common. This means
the file opens right away in a PDF viewer, without any password being entered. We've
banned the user from doing anything other than viewing the file (see
“Encryption and
Decryption” on page 113
for details of the
pdftk
syntax for permissions and different
encryption types).
When the file is opened in Adobe Reader, the only noticeable change is that
(SECURED)
is appended to the window's title bar. By opening the
File...Properties
window, and choosing the
Security
tab, the security properties can be viewed—see
Figure 8-1
. A more technically-minded display is obtained by clicking on the
Show
Details...
button to bring up the window shown in
Figure 8-2
.
Figure 8-1. Security properties display in Adobe Reader for encrypted.pdf
