An image encryption scheme employing quick response codes

An asymmetric image encryption scheme combining the concepts of interference, phase-truncation in Fresnel domain, and quick response (QR) code is proposed. The initial scrambling of the input image is carried out using Arnold transformation. The scrambled image is divided into pixel blocks. Each block gets encoded into a QR code that are multiplexed to form a binary matrix. Phase truncation is applied to the binary matrix which gets encoded into two phase-only masks (POMs). During decryption the POMs are combined together to obtain the binary matrix, which is grouped into QR codes and decoded into pixel blocks. The pixel blocks are recombined and descrambling operation retrieves the decrypted image. The scheme is secure and tolerant to noise. Encryption has been carried out digitally, while decryption may be realized using an opto-electronic setup.