Berlin key

The key was a solution to the problem of access via communal doors of such blocks (Mietskaserne) as early as the 19th century.

[1] The system was invented by the Berlin locksmith Johannes Schweiger[2] and mass produced by Albert Kerfin & Co, starting in 1912.

According to Latour, this technical object is a decisive agent that can mediate the relationship between the tenants, users, and visitors of a building.

[5] He also proposed that the key performs a "program of action" or a "script", which is "Please bolt the door behind you during the night and never during the day".

[6] Another interpretation noted that the key reveals two social dichotomies as it draws the line between guarded and unguarded resources as well as between inhabitants and strangers.