Before revision:  In this paper, we studied Knock Codes security asking participants to select codes on mobile devices in three settings: a control treatment, a blacklist treatment, and a treatment with a larger, 2x3 grid.
After revision:  In this paper, we studied Knock Codes security asking participants to select codes on mobile devices in three settings: a control treatment, a blocklist treatment, and a treatment with a larger, 2x3 grid.