Decentralized applications (DApps) built on blockchain technology offer a promising solution to issues caused by centralization. However, traditional DApps leveraging off-chain storage face performance challenges due to factors such as storage location, network speed, and hardware conditions. For example, decentralized storage solutions such as IPFS suffer from diminished download performance due to I/O constraints influenced by data access patterns. Aiming to enhance the Quality of Service (QoS) in DApps built on blockchain technology, this paper proposes a blockchain node-based distributed caching architecture that guarantees real-time responsiveness for users. The proposed architecture ensures data integrity and user data ownership through blockchain while maintaining cache data consistency through local blockchain data. By implementing local cache clusters on blockchain nodes, our system achieves rapid response times. Additionally, attribute-based encryption is applied to stored content, enabling secure content sharing and access control, which prevents data leakage and unauthorized access in unreliable off-chain storage environments. Comparative analysis shows that our proposed system achieves a reduction in request processing latency of over 89% compared to existing off-chain solutions, maintaining cache data consistency and achieving response times within 65 ms. This demonstrates the model’s effectiveness in providing secure and high-performance DApp solutions.

Online social networks (OSN) that gather diverse interests have attracted a vast user base. However, centralized online social networks, which house vast amounts of personal data, are plagued by issues such as user privacy and data breaches, tampering, and single points of failure. The centralization of social networks results in sensitive user information being stored in a single location, making data breaches and leaks capable of simultaneously affecting millions of users who rely on these platforms. Therefore, research into decentralized social networks is crucial. However, blockchain-based social networks present challenges related to resource limitations. This paper proposes a reliable and scalable online social network platform based on blockchain technology. This system ensures the integrity of all content within the social network through the use of blockchain, thereby preventing the risk of breaches and tampering. Through the design of smart contracts and a distributed notification service, it also addresses single points of failure and ensures user privacy by maintaining anonymity. Furthermore, it tackles the scalability concerns associated with blockchain-based systems due to excessive computing resource utilization by improving the off-chain storage structure. By adopting Bloom filters and off-chain storage, it effectively alleviates the burden on on-chain storage. Comparative analysis with related studies demonstrates a minimum of 74% cost savings during post uploads. While the proposed system exhibits slightly slower write performance by 10% compared to existing systems, it showcases 13% faster read performance and achieves an average notification latency of 3 seconds. Thus, this system addresses scalability issues present in blockchain-based systems. It offers a solution that enhances data management not only for online social networks but also for resource-constrained system of blockchain-based IoT environments. By applying this system, data can be managed securely and efficiently.