Visualizing protocols is not only useful as a step towards understanding and ensuring security properties, but is also a beneficial tool to communicate notions of security to decision makers and technical people outside the field of cryptography. We present a simple card game that is a visualization for a secure protocol for private polling where it is simple to see that individual responses cannot be traced back to a respondent, and cheating is irrational. We use visualization tricks to illustrate a somewhat complex protocol, namely the Cryptographic Randomized Response Technique protocol of Lipmaa et al. While our tools cards is new. As part of visualizing the protocol, we have been able to show that, while cut-and-choose protocols normally get more secure with an increasing number of choices, the protocol we consider -- surprisingly -- does not. This is true for our visualization and for the real protocol.
Keywords: card game, polls, privacy, randomized response technique, rational equilibrium, voting.