I wrote a blog post a few days ago about using Evolution Mail client and GPG and I partly talked about how to encrypt files. If say I already opened the compose window and partly proceeded to type off my email and then remember I want to send an attachment with it, that's how I would do it.
It turns out that nautilus, the default file browser in Ubuntu can help me if i want to encrypt a file. Put the focus on the file you want to encrypt.
You can either right-click and choose encrypt from the pull-down menu or hit the pull-down key (right side of the keyboard, next to the control key) in my pc.
I'm using Ubuntu 14.04 lts Unity desktop. If you're using a different desktop environment, you might try exploring your file browser. GPG is standard in any Linux distro. Also, if it's the first time you're doing this, it might prompt you to download needed nautilus add-ons, so just answer yes. In my case, I downloaded seahorse-daemon, libcryptui, and seahorse-nautilus as needed by my system.
When it finishes installing the packages, a much better integration between Seahorse (GPG key manager) and nautilus ( file browser) makes it easier to encrypt files.
GPG for Windows Users
Evolution And GPG
Say No To Mass Surveillance
E-Mail Self Defense
Mailvelope Encryption for Webmail
We Need To Take Back Our Emails
| -- |
Protect yourself and your family (and friends). Encrypt the web. Use GnuPG.
My Public Key is
79E0 8EB7 F171 BC7C 436A
4091 C503 2ABC 415E 88DB
If you don't know what I'm talking about. This blog may help you. Try this infographic.