Obric: Oblivious Keyword Search in Hyperledger Fabric Platform

Access pattern disclosure can reveal sensitive information related to search queries, posing a threat to user privacy. Malicious attackers may infer users’ search intentions, behavior, and interests from access patterns, which can be used for targeted attacks, phishing, or identity theft. Access pattern disclosure may also jeopardize the confidentiality of the searched data, as it may reveal sensitive information related to the queried data. Traditional searchable encryption allows for searching encrypted data directly, but suffers from privacy leaks due to access pattern disclosure and cannot guarantee data integrity. Additionally, traditional searchable encryption only supports single-keyword search and leads to significant computational overhead when searching for a large number of ciphertexts. To address these issues, we propose a two-stage protected ciphertext retrieval scheme called Obric that supports oblivious multi-keyword search in hyperledger fabric platform. In specific, we store encrypted data using the distributed point function (DPFs) on the Order node set and the ORAM encryption algorithm on the Peer nodes. Finally, we implement a secret information storage system so that users’ access pattern privacy is not compromised by malicious adversaries.