Code-Wall
From Tardis Wiki, the free Doctor Who reference
A code-wall was a piece of technology that only allowed certified beings to enter its space.
The private guest suites of Platform One were protected by code walls. (TV: The End of the World)
The Tenth Doctor suggested River Song establish a code-wall around the Library when the Vashta Nerada started to kill the crew of her expedition. (TV: Silence in the Library)
