With the default Apache HBase configuration, everyone is allowed to read from and write to all tables available in the system. For many enterprise setups, this kind of policy is unacceptable.
Administrators can set up firewalls that decide which machines are allowed to communicate with HBase. However, machines that can pass the firewall are still allowed to read from and write to all tables. This kind of mechanism is effective but insufficient because HBase still cannot differentiate between multiple users that use the same client machines,