New Steganography Concept: Blockchain Steganography
Steganography is the science of data hiding and it is a very old subject of the scientific study topic. The name steganography comes from the Greek word steganographia (derived from the words steganós and graphia). Considering all the steganography examples made throughout history, the most prominent feature of steganography is that the information (secret message) is hidden in sight but inconspicuously.
After the emergence of computers and the transformation of information into data, steganography techniques have also changed and the concept of digital steganography has emerged. Secret messages have been tried to be hidden on a selected cover-multimedia and various techniques have been developed to do this. Today, technical steganography studies are carried out in image, text, video, and audio file types. As can be understood, the science of steganography can adapt to the new reality that has emerged with the increase in technological capabilities and introduces new steganography techniques.
In the image below, sub-breakdowns of security systems are shared. As can be seen, the two main subheadings are cryptology and information hiding. When the steganography studies in the literature are examined, it is seen that the secret message is mostly used in steganographic techniques after being encrypted with an encryption algorithm. The reason for this is that in case of detecting stego-multimedia in any way (with steganalysis methods), the hidden data cannot be easily obtained. Steganography and watermarking appear under the heading of information hiding. As the name suggests, watermarking is a type of maker method and is used to identify ownership of the copyrights. Finally, steganography is studied by breaking it into two sub-titles, linguistic and technical.
Blockchain technology is a very ideal new technological development for steganography studies. Blockchain technology is a joint study of computer science and cryptology sciences. Its foundation can be traced back to the advent of Internet networks. The success achieved after the Bitcoin protocol was proposed by Satoshi Nakamoto in 2008 has contributed greatly to the attraction of blockchain technology. Blockchain technology is an immutable ledger technology with a decentralized, peer-to-peer, and distributed architecture. It is a different and new type of database. The fact that blockchain technology can be applied in almost every field via smart contacts is a very positive development for the science of steganography.
The fact that blockchain technology is applied in many areas provides great convenience for the data that constitutes the essence of steganography to be hidden unnoticed. In this context, various methods have been tried to hide data in blockchain blocks in the literature. However, it is not possible to talk about a study that can be considered successful, except for a few examples. In one of the studies, A novel and robust hybrid blockchain and steganography scheme (please check the study for technical details), the concept of blockchain steganography was introduced for the first time and a new data-hiding method in accordance with the spirit of steganography was proposed. In this system, which consists of two methods as OTA-Steganography and OTA-Chain, it is proposed to hide the data without being detected thanks to blockchain technology.
Blockchain steganography is the general name given to steganography studies performed in the blockchain environment. It can be done using traditional technical steganography methods in NFTs or blockchain blocks. Another blockchain steganography method is the OTA algorithm. OTA algorithm does not cause any change in cover multimedia. For this reason, even if it is known that the obtained file is stego-multimedia, the hidden data cannot be detected. The reason for this is the bit-level marking in the OTA algorithm. The marked bit indices are transmitted to the receiver in the private-OTA-Chain. It is not possible to obtain the hidden data without the index information of the receiver. In this context, it is not possible to detect blockchain steganography made with the OTA algorithm by any steganalysis method. Also, the hiding capacity problem seen in cover-multimedia’s has been eliminated. It is possible to hide secret-message in very high dimensions inside cover-multimedia. However, the proposed OTA algorithm is not perfect in its current form and is open to improvement in terms of scalability and ease of use.
Another interesting example of blockchain steganography studies is NBS: NFT-Based Blockchain Steganography. In this study, which will be published at the 2nd International Conference on Computing, IoT and Data Analytics, a traditional image steganography has been made, unlike the OTA study, by using NFTs as cover-images. With the LSB technique, the 1 KB secret message is hidden in the Generative Art NFTs specially produced for this academic study. (Since the study has not been published yet, those who want to examine it should send me an e-mail.) Solana was chosen as the blockchain platform in the NBS study. Solana is a platform with smart contract capability and a highly preferred platform with very reasonable transaction costs. The generated Generative Art NFTs code was developed in Processing Programming Language. Finally, instead of the Generative Art NFTs used in this study, it is interchangeable with fractional NFTs, Bitcoin Ordinals, and all types of NFTs.
In this medium article, it is necessary to mention the OTA 2.0: An Advanced and Secure Blockchain Steganography Algorithm study, which was accepted at the 5th International Conference on Natural and Applied Science and Engineering (ICNASEN 2023) and will be published soon. OTA 2.0 is an improved version of the OTA algorithm introduced in our article. Hyperledger Fabric permissioned blockchain platform is used in OTA 2.0. It can work with all types of cover-multimedia. Secret messages are encrypted using Vernam Cipher. In addition, an innovative solution for key sharing is proposed in the study. OTA-Steganography algorithm is implemented in HLF chain codes. OTA 2.0 differs positively from the old version with its block creation times, increased block size, and zero transaction cost. Since the study has not been published yet, those who want to examine it should send me an e-mail.
About Me:
He received his undergraduate degree from Istanbul Aydın University Computer Engineering Department in 2014. He received his master’s degree from Istanbul Aydın University, Department of Computer Engineering in 2016, which was named “Comparing Clustering Algorithms on WEKA and MATLAB with Several Datasets.” He received his Ph.D. degree from Istanbul Aydın University, Department of Computer Engineering in 2022, which was named “Highly secured information exchange algorithm using encryption and steganography techniques, based on blockchain technology.” He worked as an academician at Istanbul Aydın University Engineering Faculty Computer Engineering Department between 2019–2022, worked as the manager of the İAU Blockchain Application and Research Center between 2020–2022, and held many international conferences and webinars. His research interests include data science, data security, and blockchain technology. As of 2022, he has been working as a Blockchain Specialist at TÜBİTAK BİLGEM Blockchain Research Laboratory.