# A Dynamic Multi-Layer Steganography Approach Based on Arabic Letters' Diacritics and Image Layers
## 3 The Proposed Approach  
This paper proposes a robust and multi-layered algorithm to hide information of limited size which is highly confidential and important, such as in military applications. Through our research, we aim to provide a solution that is more effective than the previous solutions in the steganography process by using the properties of the Arabic language. We focus on hiding confidential information in the diacritics of Arabic letters and Hamzas in more than one scenario. This will have a significant impact on the amount of text to be hidden and its robustness on the one hand, and on the other hand, we focus on the variety of hiding scenarios. In addition, for the text to be highly protected, we rely on the method of multi-layering. We first encrypt the text, hide it within a text cover, encrypt the result  
Figure 7: Example for diacritics direction method. and then embed it within an image cover. The proposed layers provide added protection to maintain the confidentiality of the hidden text. To recover the hidden message, the receiver reverses the previous steps. The rest of this section presents the stages of the embedding process in some detail, starting by presenting the prototype of our proposal, which consists of four layers, as shown in Figure 8.  
**Phase 1: Encrypting secret data using AES**  
At this phase, to increase the complexity of steganography analysis, the secret will be encrypted using the AES algorithm [49]. **Phase 2: Embed the encrypted data into the Cover**  
In the process of hiding confidential information, we will follow two different scenarios, one of which can be chosen according to the nature of the application or data, as follows:  
**First scenario:** This scenario depends on the diacritics used in the Arabic language in a way that is unique compared to other languages. Therefore, storing the encoded data resulting from the first step in the form of zeros and ones will depend on changing some parsing characters. For example, the diacritic will be changed to a Fatha (\(\circ\)) in the case of 0 and to a Dammah (\(\hat{\circ}\)) in the case of 1. However, the switch within the diacritics will be in an agreed sequence (Like Table 3) between the two parties (the sender and the receiver), in the sense that there is a map agreed upon between the two parties in the exchange places for information. \begin{table}
\begin{tabular}{l c c c c c c c c c c c c c} \hline \hline
**The bit number of the secret message to be hidden** & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & \\ \hline
**The number of the diacritic used in concealment** & 1 & 5 & 50 & 70 & 71 & 72 & 80 & 100 & 102 & 104 & 105 & 106 & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Example for sequences of positions for hiding. Figure 8: Layers of the proposed approach. Thus, it is very difficult for any opponent to know where the data are embedded into the text, especially since some diacritics will not change despite the data being embedded. Thus, even an expert in the Arabic language, in the event of suspicion that the text contains hidden information, will be able to discover only a small number of the zeros and ones, through which they cannot decipher the secret information embedded within the text. It would also be impossible for automated analysis systems. However, one of the disadvantages of this method is the need to agree on a map of substitutions between the two parties, which may not be available in some circumstances. Therefore, another scenario was proposed to solve such cases. **Second scenario:** The letter Alif () in Arabic is written in more than one way, as in the following figure. In some places, this letter is written with a Hamza, i.e., decorated with a Hamza above or below. These Hamza (in the Arabic language) have two types, so can either be called a disjunctive Hamza () or a conjunctive Hamza (). The conjunctive Hamza draws the letter Alif without a Hamza, while the disjunctive Hamza is drawn at the top (Figure 9).