Key

A physical key is present in subroutine_hello. Inserting it activates Sourcebox.

Several events cite errors regarding keys or authentications:

#theory EMInside, potentially
gravelgrave with ent_dmnpc_anomi4e_UNREGISTERED
psbmod after crossing the Chomsky Doorway at Bedrock
A physical key (matching the prop) is present in Xemu's kulcs states