Thanks everyone for the feedback so far. At this point, I'd like to start a vote for KIP-38.
Summary: Add support for ZooKeeper authentication KIP page: https://cwiki.apache.org/confluence/display/KAFKA/KIP-38%3A+ZooKeeper+Authentication <https://cwiki.apache.org/confluence/display/KAFKA/KIP-38:+ZooKeeper+Authentication> Thanks, -Flavio