Abstract: The quick response code (QR code) is a type of two-dimensional barcode known for its fast decoding speed and strong error correction capability, and it has been widely applied in various fields of daily life. However, due to the publicly available encoding rules of QR codes, when using QR codes as a carrier for transmitting secret information, some previous related schemes have faced issues such as leakage of secret information and limited payload capacity. To address these problems, this paper pro- poses a new information hiding scheme for QR codes. This scheme combines a Sudoku matrix to design a new mapping function and extends the traditional (7,4) Hamming code to develop a corresponding flipping rule table. On the basis of ensuring correct interpretation of the public information in the QR code, it achieves a higher level of decryption difficulty and greater information hiding capacity. Experimental analysis shows that the constructed codeword mapping function can prevent attackers from cracking the secret information based on the carrier QR code. Compared with existing steganography schemes, this scheme improves both the embedding payload capacity and the decryption difficulty coefficient.

Key words: information hiding, Sudoku Matrix, Hamming code, QR code