Joint Image Encryption and Screen-Cam Robust Two Watermarking Scheme

Abstract

This paper proposes a joint encryption and screen-cam robust watermarking scheme. This method combines the advantages of smartphone, encryption and watermarking technologies, thereby achieving watermark extraction with a smartphone, partial decryption and tracking leakage from sneak shots. We design a dual watermarking algorithm to achieve watermark detection from both encrypted and decrypted images. First, a watermark is embedded in the discrete Fourier transform (DFT) domain to enable leakage tracking. Then, a second watermark is generated based on QR (Quick response) code encoding and inverse DFT to achieve high watermark capacity and error correction ability, where the secret key for decryption is included in the watermark message. By hiding this message carrying the watermark for the encrypted image in the changes caused by embedding the first watermark, we can improve imperceptibility and will not affect the effectiveness of the proposed scheme. Finally, to enhance the robustness of watermark after encryption, a chaotic mapping-based segment encryption algorithm is proposed. In the process of watermark detection, to cope with perspective correction, a frame locating based algorithm is employed to achieve watermark synchronization from a recaptured picture of the encrypted image. Considering the severe quality degradation, we use a noise component and local statistic feature-based method to extract the message bits. The experimental results show that the proposed scheme is secure, and highly robust, to screen-cam the process for both before and after decryption. Additionally, after decryption, the proposed scheme also has high robustness against common image processing attacks.

Fourier Image Watermarking: Print-Cam Application

“…However, the testing results did not demonstrate resistance to projective distortions. Chen et al [7,31] proposed a watermarking method for screen-cam systems, where a camera device is used to generate content displayed on screens into digital signals. The method is based on using DFT to fix the synchronization problems.…”

Hybrid chaotic map with L-shaped fractal Tromino for image encryption and decryption

“…The watermarking method is known for its capability in retrieving the actual information without losing the significant data in it [6], [7]. The encrypted secret data is sent via internet or wireless networks to fulfill the need of securing the route of data transmission over distinct communication channels [8], [9]. Moreover, encryption of secret information prevents unapproved access, data destruction, and adjustment of data in data exchange [10], [11].…”

Robust image watermarking in DCT domain using optimal inter‐block difference

“…The principle issues to be addressed are the distribution, tampering, and illegal copying of unprotected material, which may result in the lack of accountability for the perpetrators 4 or the misleading of justice 5 . To address these issues, digital watermarking has appeared as an alternative solution to encryption 6‐10 . In fact, encryption fails to protect contents in a hostile environment, whereas once they are decrypted by a malicious person the original issues will rise again.…”

“…5 To address these issues, digital watermarking has appeared as an alternative solution to encryption. [6][7][8][9][10] In fact, encryption fails to protect contents in a hostile environment, whereas once they are decrypted by a malicious person the original issues will rise again. However, watermarking shields media (i.e., image, audio, or video) by embedding, generally, a non-removable watermark serving to protect the media or trace back the leaker.…”