I created an app called Safe for elementary OS that allows you to create encrypted containers to hold sensitive files. It uses https://www.dyne.org/software/tomb
under the hood to handle all of the complex parts. I'm sure it has lots of bugs which you all will find and tell me about.
sudo apt-add-repository ppa:heathbar/safe
sudo apt-get update
sudo apt-get install safe
For security reasons, Safe will not work when swap is enabled. For now you can run: "sudo swapoff -a" to disable the swap. In the future, perhaps Safe will disable and re-enable your swap for you.