# A Comparative Analysis of Arabic Text Steganography
## 5 Evaluation Criteria
### Evaluation of Arabic Text Steganography Methods  
This paper presents the evaluation of Arabic text steganography methods based on the capacity, security, robustness, and invisibility criteria in Tables 20-26 and summarized below:  
* **Dot method:** Although this method enhances invisibility, it is less robust, as the hidden message may be lost if the font format is changed. In addition, the method does not consider the encryption or non-sequence embedding positions to prevent the hidden bits from extraction. Despite using compression, the capacity is still low, with the maximum embedded bits per location are two.
* **Diacritics method:** Low invisibility is the major drawback of this method. The cover text and stego text are not identical, and the stego text has many ambivalences in using diacritics. Besides that, capacity is still low, where the bits per location ranges from one to four. Whereas this method partially enhances the robustness of the stego text, the secret message is not encrypted and not embedded in non-sequence positions.
* **Kashida method:** This method is resistant against the copy-paste action but has downsides in terms of capacity, invisibility, and robustness.
* **Unicode method:** The embedding capacity of this method is decreased even though compression is used in some techniques. However, this method accomplishes high invisibility. The robustness is improved in copy-paste action, font format, and OCR, but encryption and non-sequence embedding are not considered.
* **Sharp edges method:** This method achieved high invisibility, capacity, and robustness. Adding non-sequence embedding adds more complexity to protect it from the attacker.
* **Poetry system method:** The method has high invisibility and higher robustness. However, its hiding capacity is limited.
* **Integrated method:** The primary goal of merging methods is to improve performance and overcome the previous methods' limitations. Nevertheless, if the methods are not integrated properly, then these drawbacks are inherited.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Authors**} & \multicolumn{3}{c}{**Capacity**} & \multicolumn{3}{c}{**Security**} & \multicolumn{6}{c}{**Robustness**} & \multicolumn{3}{c}{**Invisibility**} \\ \cline{2-13}  & **Bits/Location Compression Encryption** & **Sequence** & **Embedding** & **Insertion/ Deletion** & **Copy/Paste** & **Font For- mat** & **OCR** & **Printing** & **Relyping** & **Similarity Ambiguity** \\ \hline [75] & 1 & ✓ & ✗ & ✓ & ✗ & ✗ & ✗ & ✗ & ✓ & ✗ & High \\ [76] & 2 & ✗ & ✗ & ✓ & ✗ & ✗ & ✗ & ✗ & ✓ & ✗ & High & Low \\ \hline \hline \end{tabular}
\end{table}
Table 20: Evaluation of dot method based on invisibility and robustness and capacity.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Authors**} & \multicolumn{3}{c}{**Capacity**} & \multicolumn{3}{c}{**Security**} & \multicolumn{6}{c}{**Robustness**} & \multicolumn{3}{c}{**Invisibility**} \\ \cline{2-13}  & **Bits/Location Compression Encryption** & **Sequence** & **Insertion/ Embedding** & **Insertion/ Deletion** & **Copy/Paste** & **Font For- mat** & **OCR** & **Printing** & **Relyping** & **Similarity Ambiguity** \\ \hline [80] & 1 & ✗ & ✗ & ✓ & ✗ & ✓ & ✗ & ✓ & ✓ & ✗ & low & High \\ [82] & 1 & ✗ & ✗ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & low & High \\ [79] & 4 & ✓ & ✗ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & low & high \\ [81] & 4 & ✗ & ✓ & ✓ & ✓ & ✓ & ✓ & ✗ & ✗ & Low & High \\ [83] & 1 & ✗ & ✗