Minecraft wiki entry for Blast_Furnace, associated text: In Java Edition, a blast furnace can be "locked" by setting its Lock tag using the /data command. If a blast furnace's Lock tag is not blank, the blast furnace cannot be opened unless the player is holding an item with the same name as the Lock tag's text. For example, to lock a blast furnace at (0,64,0) so that the blast furnace cannot be opened unless the player is holding an item named "Blast Furnace Key", use /data merge block 0 64 0 {Lock:"Blast Furnace Key"}.