"Anyone can generate a QR code. Designing one that actually prevents misuse is the hard part." When people hear "QR-based attendance," the first question is usually: "Can't someone just take a photo of the QR code and send it to their friend?" The...

Traditional attendance systems seem simple until you look at how they work in practice. Manual roll calls consume valuable class time, paper attendance sheets are inefficient, and many QR-based systems can still be exploited through proxy attendance....