## 2 Related Work
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Web of Science** & **IEEE** & **Sage** & **Science Direct** & **MDPI** & **Wiley** \\ \hline \multirow{3}{*}{**Search Term I**} & Cloud * AND & Cloud * AND & Cloud * AND & Cloud * AND & Cloud AND & Cloud * AND & Cloud AND \\  & Blockchain * AND & Blockchain * & Blockchain * & Blockchain AND & Blockchain AND & Blockchain * & Blockchain AND \\  & Trust * & AND Trust * & AND Trust * & Trust & AND Trust * & Trust \\  & Cloud * AND & Cloud * AND & Cloud * AND & Cloud * AND & Cloud * AND & Cloud * AND \\  & Blockchain * AND & Blockchain * & Blockchain * & Blockchain AND & Blockchain * & Blockchain AND & Blockchain AND \\  & Compliance * & Compliance * & Compliance & Compliance & Compliance * & Compliance \\  & Publication Title & Publication Title & Publication Title & Publication Title & Publication Title & Publication Title \\  & Abstract & Abstract & Abstract & Abstract & Abstract & Abstract \\
**Additional** & \begin{tabular}{c} Articles, \\ Proceedings Papers, \\ Review Articles \\ \end{tabular} & \begin{tabular}{c} Journals, \\ Conferences \\ \end{tabular} & \begin{tabular}{c} Research Article, \\ Review Article, \\ Research Article \\ \end{tabular} & \
\begin{tabular}{c} Review articles, \\ Research articles \\ \end{tabular} & Article, Review &
\begin{tabular}{c} Journals \\ \end{tabular} \\ \hline HITS & 757 & 465 & 165 & 65 & 25 & 18 \\ \hline \hline \end{tabular} Note: Multiple-character wildcard searches with * look for zero, one, or more characters.  
\end{table} 
Table 1: Knowledge database. Figure 1: Identified word groupings. Figure 2: LDA group word counts. An approach that dates back to 2018 was presented by [PERSON] et al. [21]. The authors implemented communication via the blockchain using a programmable interface. The GET and PUT functions could ensure transparent communication with an untrusted domain. This work utilizes the approach of a programmable interface to communicate with an untrusted environment. [PERSON] et al. [22] presented a blockchain-based system that secures orchestration operations in virtualized networks, ensuring audibility, non-repudiation, and integrity. In this context, the work presented here takes the approach of non-repudiation and data integrity, and extends it with an automated approach to blockchain/cloud communication. Several studies aiming to increase trust by using blockchain technology have been published. [PERSON] et al. [23] provided a comprehensive overview of the software engineering applications enabled by blockchain technology. The presented overview provided an initial overview of relevant works for this article. In [24], the authors presented a public mutual audit blockchain (PMAB) for outsourced data in cloud storage. [PERSON] et al. [25] proposed a blockchain-based publicly verifiable data migration scheme supporting cloud integrity checks. [PERSON] et al. [26] introduced a blockchain-based ciphertext-policy attribute-based encryption scheme for cloud data security sharing. Addressing the trust problem between data owners and cloud service providers, [PERSON] et al. [27] proposed a collaborative auditing blockchain framework for cloud data storage, and showed that their framework has the advantage of preserving remote data integrity from various attacks. Targeting blockchain-based data sharing, MedChain [28] is one of the first methods implemented for sharing a large amount of data via blockchain. [PERSON] et al. proposed a method to manage system operations using a smart contract for blockchain-based systems [29; 30]. The smart contract \"OpsSC\" manages an operational item's operational rules and configuration parameters in their proposed method. In addition, operational agents execute operations based on the smart contract, and record the results and evidence of the execution on the chain. Within their study, the authors described system backups as a one-use case.