When conducting surveys, an Administrator might send an Enumerator to survey a Respondent. For "sensitive" questions (e.g. about embarrassing behavior), the Respondent may be fine with the truth being revealed to the Administrator but not to the Enumerator.
Is there a way to create a one-way function/process using simple (small and cheap) physical objects such as pen and paper that isn't too time-consuming or involves complex math? Inverting the function would be too hard for the Enumerator during, or just after the survey, but the Administrator could do it later. Assume that the Enumerator can do anything quickly to uncover the answer (e.g. "accidentally" open a sealed envelope or claim non-random data is random) so long as the Administrator gets the truthful answer in the end. Assume that this is the only interaction with the survey, so no secret information has been passed among the Administrator and the Respondent. FYI: Previous questions include ones about non-computer/manual full cryptosystems and ciphers, but answers to both involve a long time to execute.