Abstract: QR codes are widely used due to their large information capacity, fast decoding speed, and error tolerance capability. However, because their decoding rules are publicly available, they are prone to privacy leakage. To address this issue, this paper leverages the fundamental properties of QR codes to propose an information-hiding scheme for QR codes based on overlapping Hamming codes to protect sensitive information within QR codes. This scheme uses a two-level grayscale QR code, transformed from a standard black-and-white QR code, as the carrier, reducing the extent of modifications to the information-hiding locations and enhancing the invisibility of the secret information. Additionally, an overlapping (16, 11) Hamming code algorithm and a corresponding codeword modification rule table are designed to hide a greater number of secret bits. Compared to existing approaches, the proposed scheme achieves superior performance in terms of secret payload capacity and embedding efficiency, while simplifying  processes of information hiding and extraction.

Key words: QR code, information hiding, overlapping Hamming code, Logistic chaotic map