VoFSQ: An Efficient File-Sharing Interactive Verification Protocol

This paper explores the possibility of improving the verification of file-sharing qualification in Blockchain-based File-Sharing system. Previous work, such as Filecoin, proposes an interactive protocol for file storage scenario. It enables file-holders to prove that the file is stored in independent storage without disclosing the content of the file. However, it uses a heavy cryptographic machinery zk-SNARKs and needs a trusted third party to generate public parameters. This paper proposes an efficient file-sharing verification protocol: Verifications of File-Sharing Qualification (VoFSQ). VoFSQ allows file-holders to verify with each other whether the shared-file has been preserved for a period of time. Users who compete for file-sharing qualification need to spend a certain amount of computing and storage resources to generate the shared-files based evidence files. Take into the cost into account, users will prefer using idle hard disk to preserve the evidence file continuously other than delete and regenerate it. Compared to the protocol of Filecoin, VoFSQ is more efficient in the prover and verifier proof phases. Meanwhile, VoFSQ does not disclose the private information of shared-file, and does not rely on trusted third parties. This paper also implements and tests VoFSQ, experimental results show that protocol can be executed efficiently.