支持去中心化存储的分块可搜索对称加密OA北大核心CSTPCD

Searchable encryption has undergone years of development to facilitate searching and even complex operations on ciphertext data.However,with the popularity of block-wise decentral-ized storage applications,existing searchable encryption schemes do not meet efficiency requirement.Particularly,when dealing with large indexes,retrieving entities must download the entire index file,leading to a significant low efficiency.To address this issue,this paper proposes a searchable symmet-ric encryption scheme based on block-wise encrypted indexes.By introducing a two-level index,only index blocks containing the keywords are accessed during retrieval,thereby significantly enhancing search efficiency.Furthermore,through the integration of blockchain and smart contracts,the pro-posed scheme can establish a fair transaction environment between data owners and users,effectively meeting the application requirements of ciphertext retrieval in decentralized storage.Experimental re-sults demonstrate that the proposed scheme achieves search efficiency dependent only on the number of documents hit by the search keywords,particularly in scenarios with large document collections.Additionally,it offers advantages in terms of storage overhead,computational cost,Gas consumption,and other metrics.