encfs is not available on the default yum repository (I run a micro instance), but it's in the Extra Packages for Enterprise Linux (EPEL) repository. See Amazon's own FAQ on enabling that repository, then all you need is to run yum
:
sudo yum install fuse-encfs
As of writing this installs encfs 1.7.4 for you. It's hassle-free, and so it's good.