Enabling Verifiable Search and Integrity Auditing in Encrypted Decentralized Storage Using One Proof

Due to the properties of autonomy and scalability, decentralized storage networks (DSNs) leveraging blockchain technology have attracted growing attention. Integrity auditing and verifiable searchable encryption are two essential functions for DSNs. The former ensures reliable and fair storage services, while the latter enables users to conduct keyword searches over encrypted data and guarantees the public verifiability of search results. However, all existing research in DSN has focused either on integrity auditing or on verifiable searchable encryption separately. In this paper, we propose a novel scheme for encrypted decentralized storage that simultaneously supports verifiable search and integrity auditing. It employs a unified proof and supports one-time proof verification to validate both the correctness of the returned file identifiers and the integrity of the files associated with these identifiers. As a result, compared to previous schemes supporting only integrity auditing, our scheme maintains a similar proof size and the support for search result verification does not significantly increase the on-chain storage overhead. Additionally, our scheme allows users to dynamically update their outsourced files while ensuring forward security during the file insertion process. We formally analyze the correctness and security of our scheme, and implement a system prototype to evaluate its performance. The experimental results demonstrate that it achieves verifiable searchable encryption and integrity auditing with practically affordable overhead.