Multi-secret Steganography in QR Codes

This paper presents a steganographic scheme that conceals two independent secrets in a single QR code. The method uses two embedding algorithms which operate in separate domains. The first algorithm embeds the secret information into segments. The resulting code is then passed to the second method which modifies some modules to hide another secret, exploiting the error correction feature of QR codes. In this way, the secret messages do not overlay and are both possible to recover. The secrets may be retrieved separately as their embedding areas are different. The presented approach is an example of multi-secret steganography which may be used for confidential data transfer.