A Blockchain-Based Traceable Access Control Scheme for IPFS

The InterPlanetary File System (IPFS) has emerged as a promising platform for decentralized and resilient data sharing, with applications across diverse domains. However, the absence of native access control severely limits IPFS’s adoption for regulated or confidential data, as any peer who obtains a Content Identifier (CID) can fetch the corresponding content and reliance on CIDs alone cannot prevent unauthorized access. Existing attempts to retrofit IPFS with access control often compromise its Merkle-DAG structure or incur repeated on-chain checks, resulting in high overhead and reduced compatibility. We present RBAC-IPFS, a role-based access control framework that augments IPFS while preserving its Merkle-DAG and Bitswap workflow. RBAC-IPFS performs a single smart-contract authorization for the root CID and then enforces local verification of all linked sub-blocks through Merkle proofs. This design binds authorization to the entire file, eliminates per-block on-chain costs, and maintains native concurrency. We formally prove completeness, soundness, and no-bypass under standard cryptographic assumptions. A Dockerized prototype shows contract execution in 1–2 ms and end-to-end latency of 146–156 ms on Fabric, while Merkle proof validation remains sub-millisecond for multi-megabyte files. Compared with naïve per-block on-chain verification, RBAC-IPFS reduces 4 MB download time by 1.9×. Under adversarial conditions, it rejects injected sub-CIDs within 93–109 ms and achieves higher success rates with lower uplink usage than native IPFS during denial-of-service attacks.