QR code is designed as machine readable symbol, which is widely used in various fields of life due to its large message capacity and fast decoding speed. However, as a public standard, it will give rise to the security issue when delivering sensitive information with QR code. To overcome this weakness, this paper explores the characteristic of QR code to propose an efficient secret hiding mechanism to protect the sensitive information within QR code. The secret message would be embedded into cover QR code based on (8, 4) Hamming code. The error correction capacity (ECC) of QR code would correct the errors produced in the secret embedding procedure, and the valid marked QR code would reduce people’s curious. Compared to the state-of-art works, the proposed scheme achieves a better performance on the aspects of secret payload and embedding efficiency.

Secret image sharing (SIS) is an image protection technique based on cryptography. However, traditional SIS schemes have limited noise resistance, making it difficult to ensure reconstructed image quality. To address this issue, this paper proposes a robust SIS scheme based on QR codes, which enables the efficient and lossless reconstruction of the secret image without pixel expansion. Moreover, the proposed scheme maintains high reconstruction quality under noisy conditions. In the sharing phase, the scheme compresses the length of shares by optimizing polynomial computation and improving the pixel allocation strategy. Reed–Solomon coding is then incorporated to enhance the anti-noise capability during the sharing process, while achieving meaningful secret sharing using QR codes as carriers. In the reconstruction phase, the scheme further improves the quality of the reconstructed secret image by combining image inpainting algorithms with the error-correction capability of Reed–Solomon codes. The experimental results show that the scheme can achieve lossless reconstruction when the salt-and-pepper noise density is less than $d\le 0.02$, and still maintains high-quality reconstruction when $d\le 0.13$. Compared with the existing schemes, the proposed method significantly improves noise robustness without pixel expansion, while preserving the visual meaning of the QR code carrier, and achieves a secret sharing strategy that combines robustness and practicality.