The Quick Response System (QRS) consists of a 2-D machinereadable QR Codes and a mobile-friendly user interface. The QR Codes can be encoded to different types of information. Because of QR code’s high information density and robustness, it has gained popularity in many applications across various industries. Recently, some universities and colleges have adopted QR Code into classroom teaching, by taking advantage of its instant feedback from students, instructors may have immediate understanding of whether students have understood a concept. The QR code can be used for polling, tutorials, and quizzes. However, it is crucial to protect against personal data from disclosure and to prove student identity, especially in the event of an in-class QR Code-based quiz. In this paper, we explore some potential security breaches and privacy concerns for QR codes in classroom teaching, and propose some design requirements with respect to the QR code itself. We also suggest to apply a grouping-proof protocol to authenticate all students identity before starting a quiz. This paper sheds some lights on future research directions in QR code design and processing.