# A Novel and Robust Hybrid Blockchain and Steganography Scheme
## 3 Methodology and Proposed Method
### Proposed Ozyavas-Takaoglu-Ajlouni (OTA) Algorithm
#### 3.3.1 OTA-Steganography Algorithm
The OTA-steganography algorithm was developed with the Java programming language, while the backend component of the OTA-chain algorithm was coded with the JavaScript programming language. The coded OTA-chain system was tested using Git Bash and Postman applications. A total of 32 images were used as cover multimedia during the testing of the proposed algorithm. The testing selected cover images are 256 \(\times\) 256 pixels in size, and pictures are assigned names in the range of CI-1 through CI-32. These cover images were selected from the USC-SIPI Image Database Version 6. The selected images are illustrated in Figure 5. The data to be hidden is determined as 1 kB, 5 kB, 10 kB, and 20 kB. An example data of 1 kB is shared in Figure 6. However, big data sizes for steganographic communication such as 5 kB, 10 kB, and 20 kB were used to test the capabilities of the proposed OTA algorithm. The tests show that any data can be used because the system will perform exactly the same regardless of the data size. The type and size of cover multimedia used is of no importance to our algorithm because the first 256 \(\times\) 256 byte section is selected for the marking/indexing process. The OTA-steganography and OTA-chain algorithms, which are the two sub-titles of the OTA algorithm, are shared under the analysis Sections 4.1 and 4.2. Figure 4: Structure of OTA Algorithm. The first recorded uses of steganography can be traced back to 440 BC in Greece, when [PERSON] mentions two examples in his Histories. [PERSON] sent a message to his vassal, [PERSON], by shaving the head of his most trusted servant, marking the message onto his scalp, then sending him on his way once his hair had regrown with the instruction, When that our come to Miletus, bid [PERSON] shares why head, and look theorem. Additionally, [PERSON] sent a warning about a forthcoming attack to Greece by writing it directly on the wooden backing of a wax tablet before applying its besoursa surface. Wax tablets were in common use then as reusable writing surfaces sometimes used for shorthand. In his work Polygraphise [PERSON] developed his socalled AverflarieCipher that can hide information in a Latin prase of [PERSON]. Auctor Sapientiessinus Conservans Angelica Deferat Nobis Charitas Potassium Creatoris for example contains the concealed word NICPEDIA. Figure 5: USC-SIPI Cover Images. Figure 6: Example of 1 KB Secret Data. ### OTA-Steganography Results

Table 2 shows the results of applying the OTA-steganography algorithm with 1 kB, 5 kB, 10 kB, and 20 kB secret data and cover image number 1 (256 \(\times\) 256 pixels). The OTA algorithm results show the total array size of the marked data addresses, the number of arrays used to hide the data, and the time required. The same test was applied to the remaining 31 images. The results prove the algorithm suitability for the proposed task (complete test results can be obtained by contacting the author directly). As seen from Table 2, the cover images used have no effect on the total array size and the number of arrays created as a result of the application of the OTA-steganography algorithm. This is due to the marking/indexing process performed on an array of 256 \(\times\) 256 bytes, as the results show the cover images differ only in the time spent in the marking process. Table 2 results reveal that the differences in the bit sequences of the cover images do not cause a big difference in time, so that the cover multimedia selected in steganographic studies using the OTA-steganography algorithm does not have a significant effect on the success of the OTA algorithm. ### OTA Blockchain Results

The cover image, whose URL address is stored in the transaction data, is used by the OTA-steganography algorithm, and the address array obtained by marking 1 KB of plaintext data using 8-bit blocks is encrypted with OTP and then transmitted to the receiver using OTA-chain, as shown in Figure 7. Single OTA-chain coin was spent in the realization of this transaction.