Generation of Multi-Layered QR Codes with Efficient Compression

In this modern data-centric era, securing information that is transferred over the internet is a serious concern. Various cryptographic and stenographic methods play a vital role in this purpose. In this work, we develop a multi-layered steganographic system capable of hiding payloads in different hidden layers inside QR codes. Furthermore, each layer is compressed and encrypted separately to secure the payload data. Hence, we use the QR (Quick Response) Code as the cover medium to achieve and implement the above principles. In the proposed multi-layered QR Code approach, the top layer works as a standard QR Code while the layers beneath it act as private data. The secret is efficiently compressed to accommodate more information within the same space provided, thereby increasing the holding capacity of the QR code. The data in each layer are retrieved using different methods according to the type of compression used during the encoding process of the specified layer. The proposed model can store up to nine hidden layers of data. Various robustness tests are carried out to validate the efficiency of the hidden layers in the QR code and to check whether the hidden layers can withstand alterations without any data loss. Importantly, the resulting QR code works identically to a normal version upon scanning with any typical QR code scanner.