SlackBuildsOrg/system/tarsnap

Tarsnap is a secure cloud-based backup service featuring client-side
encryption and de-duplication created by Colin Percival.  You will need
to be a Tarsnap subscriber to use this software.

The recommended cache directory for Slackware is /var/cache/tarsnap, but
this can be changed in /etc/tarsnap.conf to suit your file scheme.

Even casual backups may contain sensitive data!  Before running the
build, please take a moment to verify the source tarball.  The Tarsnap
website has instructions for checking your copy against the release hash
and Tarsnap code signing key.