## 1 Introduction
### Contributions  
This study provides a comprehensive evaluation of blockchain-based data storage methods, addressing critical challenges related to security, scalability, and cost efficiency. By systematically comparing on-chain, off-chain, and hybrid approaches, this work highlights their applicability in various industry domains and security-sensitive environments. The following are the key contributions of this study:  
* _Comparative Analysis of Blockchain Data Storage Methods_: On-chain, off-chain, and hybrid data storage methods have been systematically compared in terms of security, cost, scalability, and performance. This comparative framework provides an in-depth analysis of security trade-offs, filling a critical gap in the literature. Additionally, the study offers insights into the scalability and cost efficiency challenges in blockchain storage solutions.
* _Security, Performance, and Industry-Specific Applicability of Hybrid Approaches_: Hybrid storage solutions, combining the strengths of on-chain and off-chain methods, have been analyzed in detail regarding their security, performance, and cost implications. Their applicability in high-security and flexible environments, such as healthcare, finance, and the Internet of Things (IoT) industries, has been specifically examined.
* _Comparative Analysis of Cryptographic Security Mechanisms and Guidelines for Blockchain Integration_: Blockchain storage methods are evaluated based on encryption, access control, and data integrity. This study explores how hashing mechanisms ensure data integrity and how access control models (e.g., RBAC, ABAC) mitigate security vulnerabilities in sector-specific applications. It also examines the role of Zero-Knowledge Proofs (ZKP) and Homomorphic Encryption in enhancing blockchain-based storage security. Furthermore, blockchain-integrated solutions like IPFS, Swarm, and Block-weave are analyzed for their security and scalability. This work provides a novel perspective on addressing data security and efficiency challenges in blockchain storage.
* _Methodological Recommendations for Sector-Specific Security Requirements_: The applicability of blockchain storage solutions across various industries has been analyzed by considering the security and scalability requirements of different sectors. The study identifies the appropriate selection criteria for on-chain, off-chain, and hybrid storage solutions based on sector-specific constraints. Additionally, the integration of authentication, access control, and encryption techniques with blockchain has been systematically evaluated.
* _Analysis of Decentralized Blockchain-Based Data Storage Systems_: The technical infrastructure, use cases, and security mechanisms of decentralized blockchain-based data storage projects, including Filecoin, Arweave, Swarm, Sia, Ankr, and Storj, have been compared in detail. Their advantages in terms of data integrity, access control, and scalability have been thoroughly examined.
* _Systematic Classification of Blockchain Data Storage Methods_: This study presents a structured classification framework that evaluates the advantages, disadvantages, and industry-specific use cases of on-chain, off-chain, and hybrid storage models. By utilizing visualization tools such as tables and diagrams, the relationships between different storage methods and their implications for security and performance are clearly demonstrated. This framework serves as a valuable reference for academic research and contributes to existing literature on blockchain storage methodologies.  
* _Future Perspectives on Blockchain-Based Data Storage Solutions_: The study provides a comprehensive assessment of the limitations of current blockchain-based data storage solutions and explores potential future advancements in the field. Scenarios in which hybrid storage solutions could gain broader adoption are discussed, along with strategies for optimizing security, scalability, and cost efficiency. This study provides a theoretical and practical basis for future blockchain storage research.