## 6 Conclusions  
A novel watermarking scheme is proposed to ensure copyright protection and authentication of images using cryptographic techniques. This scheme fuses the asymmetric encryption RSA algorithm with spatial domain schemes called the DWT and SVD algorithm. This hybrid algorithm ensures visual inspection, copyright protection, and authentication robustness. Moreover, the proposed watermarking scheme was tested with various image and signal processing attacks. The proposed method showed better results compared to related watermarking techniques. However, we only tested our method on a few image datasets. Therefore, in our subsequent works, we will attempt to add more diversified data such as medical images and include more noise attacks to provide a generalized watermarking method for the research field.  
Conceptualization, P.V.S., K.N.V.P.S.R., K.M.H. and M.M.F.; Methodology, P.V.S., K.N.V.P.S.R., K.M.H. and M.M.F.; Software, P.V.S., K.N.V.P.S.R., K.M.H. and M.M.F.; Writing--original draft, P.V.S., K.N.V.P.S.R. and M.M.F.; Writing--review & editing, K.M.H. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Image Attacks** & **Schemes** & **Lena** & **Mandrill** & **Peppers** & **Airplane** \\ \hline \multirow{6}{*}{**No Attack**} & [PERSON] et al. [4] & 1.00 & 1.00 & 1.00 & 1.00 \\  & [PERSON] et al. [27] & 0.9885 & 0.9886 & 0.9895 & 0.9879 \\  & [PERSON] et al. [28] & 0.8694 & 0.8837 & 0.9030 & 0.9025 \\  & [PERSON] et al. [6] & 0.9995 & 0.9995 & 0.9995 & 0.9995 \\  & **Proposed Method** & **1.00** & **1.00** & **1.00** & **1.00** \\ \hline \multirow{6}{*}{**Salt and** **Pepper noise**} & [PERSON] et al. [4] & 0.8458 & 0.7156 & 0.9465 & 0.9325 \\  & [PERSON] et al. [27] & - & - & - & - \\  & [PERSON] et al. [28] & - & - & - & - \\  & [PERSON] et al. [6] & 0.9916 & 0.9916 & 0.9916 & 0.9916 \\  & **Proposed Method** & **0.9887** & **0.9899** & **0.9867** & **0.9815** \\ \hline \multirow{6}{*}{**Gaussian noise**} & [PERSON] et al. [4] & 0.8489 & 0.8053 & 0.9279 & 0.9114 \\  & [PERSON] et al. [27] & - & - & - & - \\  & [PERSON] et al. [28] & 0.7955 & 0.7796 & 0.8083 & 0.7956 \\  & [PERSON] et al. [6] & 0.9905 & 0.9905 & 0.9905 & 0.9905 \\  & **Proposed Method** & **0.9914** & **0.9901** & **0.9925** & **0.9912** \\ \hline \multirow{6}{*}{**Cropping**} & [PERSON] et al. [4] & 0.8944 & 0.8946 & 0.8942 & 0.8965 \\  & [PERSON] et al. [27] & 0.9921 & 0.9860 & 0.9948 & 0.9888 \\  & [PERSON] et al. [28] & - & - & - & - \\  & [PERSON] et al. [6] & - & - & - & - \\  & **Proposed Method** & **0.9869** & **0.9885** & **0.9891** & **0.9878** \\ \hline \multirow{6}{*}{**Scaling**} & [PERSON] et al. [4] & 0.9827 & 0.9956 & 0.9980 & 0.9963 \\  & [PERSON] et al. [27] & 0.9837 & 0.9742 & 0.9768 & 0.9879 \\ \cline{1-1}  & [PERSON] et al. [28] & 0.9263 & 0.9675 & 0.9644 & 0.9381 \\ \cline{1-1}  & [PERSON] et al. [6] & 0.9940 & 0.9940 & 0.9940 & 0.9940 \\ \cline{1-1}  & **Proposed Method** & **0.9954** & **0.9957** & **0.9955** & **0.9958** \\ \hline \multirow{6}{*}{**JPEG**} & [PERSON] et al. [4] & 0.9053 & 0.8983 & 0.8819 & 0.8956 \\  & [PERSON] et al. [27] & 0.9457 & 0.6537 & 0.9194 & 0.9472 \\ \cline{1-1}  & [PERSON] et al. [28] & 0.8469 & 0.8469 & 0.8901 & 0.8854 \\ \cline{1-1}  & [PERSON] et al. [6] & 0.9928 & 0.9928 & 0.9928 & 0.9928 \\ \cline{1-1}  & **Proposed Method** & **0.9949** & **0.9932** & **0.9932** & **0.9936** \\ \hline \hline \end{tabular}
\end{table}
Table 5: Comparison of NCC values with related watermarking methods.