  We demonstrate IFTT-PIN, a self-calibrating version of the PIN-entry method
introduced in Roth et al. (2004) [1]. In [1], digits are split into two sets
and assigned a color respectively. To communicate their digit, users press the
button with the same color that is assigned to their digit, which can be
identified by elimination after a few iterations. IFTT-PIN uses the same
principle but does not pre-assign colors to each button. Instead, users are
free to choose which button to use for each color. IFTT-PIN infers both the
user's PIN and their preferred button-to-color mapping at the same time, a
process called self-calibration. Different versions of IFTT-PIN can be tested
at https://jgrizou.github.io/IFTT-PIN/ and a video introduction at
https://youtu.be/5I1ibPJdLHM.
