Hi Adrian -
The one method I know of (there're probably more/others), using GnuPG which is also used by Sylpheed for email encryption:
I have a file some_text.txt and my PGP key is tied to my email address
[email protected]. To encrypt I open a terminal and type
Code:
gpg --recipient
[email protected] --encrypt some_text.txt
This will create a new file
some_text.txt.gpg that has been encrypted to my private key (i.e. by using my public key). To decrypt I use
Code:
gpg --decrypt some_text.txt.gpg > some_filename.txt
I will be asked for the pass phrase for my private key and the decrypted text (which by default goes to stdout/the screen) will be redirected redirected to the file
some_filename.txt.
Note that only you/your private key will be able to decrypt the encrypted file. If you want to encrypt the file for someone else you will have to use their public key for encryption (by specifying their email address with --recipient option and having imported their public key from a key server or some source). You can also encrypt to multiple recipients (for example, if you want to encrypt for someone else but want yourself be able to decrypt the file again).
NX comes with "Seahorse", an application to manage different public keys on your keyring (Manta -> Accessories -> PGO Encryption Keys)