A Survey on Blockchain and IPFS-Based Decentralized Encrypted File Sharing Systems: Architectures, Security, and Access Control

The rapid digitization of data exchange has intensified the need for secure, private and censorship-resistant file sharing solutions. Traditional centralized storage platforms such as Google Drive and Dropbox remain susceptible to single point failure, unauthorized server-side access and regulatory data disclosure, making them unsuitable for privacy-sensitive environments. Blockchain and Interplanetary File Systems (IPFS) have emerged as promising alternatives that remove centralized rights by distributing both storage and access control over peer-to-peer networks. Integration of wallet-based authentication by MetaMask, smart contract-implementation permits on the item blockchain, and content-⇢ dressed IPFS storage makes a unified architecture, referred to here as ChainLock, which provides tamper-clear file ownership, transparent, central interdisciplinary audit ⇢ access. The current implementation of such systems faces challenges that have not been addressed in smart contract gas overhead, the availability of IPFS content under the participation of sparse peers, and the barriers to utility for non-technical users. This paper surveys existing centralized and decentralized file sharing architecture, evaluates cryptographic and blockchain-based access control systems, and presents the chainlock system as a practical Web3 implementation. Future guidelines are also identified towards layer-2 scaling, client-side encryption and improved onboarding.