Comment 1 for bug 1547284

If the property name matches the Heat property name exactly, it will be mapped through to the OS::Neutron::Port object by heat-translator with no additional translation required. If the property name does not match the Heat property name, it will need to be modified by Tacker either before or after the HOT template is created by heat-translator.

So it might be easier to just make the property name "port_security_enabled", though it does raise the larger issue of tying the TOSCA node definition too closely to Heat. On the other hand, using different names for properties just because they are different than what Heat uses doesn't make a lot of sense either. I'm not making the argument either way, just wanted to lay out the two scenarios.