GnuPG is a great tool to encrypt texts and files and you can use it with PHP, only if you install it succesfully.

First, you will get this error : Fatal error: Class ‘gnupg’ not found in ….

OK the lib is not installed, do it with pecl

pecl install gnupg

But you will also have this error :

configure: error: Please reinstall the gpgme distribution
ERROR: `/tmp/pear/temp/gnupg/configure' failed

You need to install the libgpgme too !!!

apt-get install libgpgme11-dev

Now retry to install gnupg

pecl install gnupg

It should be OK.

Don’t forget to modify your php.ini file to load the extension

extension=gnupg.so

And of course, restart your apache web server

/etc/init.d/apache2 restart