Availability of GnuPG

I tried to install GnuPG via the package installer opkg. Apparently this package doesn’t exist.
Is there a possibility to install GnuPG or an alternative?

gnupg can be build and added using OpenEmbedded. To add it to the image, add the below line to ~oe-core/build/conf/local.conf

IMAGE_INSTALL_append = " gnupg"

and then build the image.