Searchable symmetric encryption(SSE)has been introduced for secure outsourcing the encrypted database to cloud storage,while maintaining searchable features.Of various SSE schemes,most of them assume the server is hon...Searchable symmetric encryption(SSE)has been introduced for secure outsourcing the encrypted database to cloud storage,while maintaining searchable features.Of various SSE schemes,most of them assume the server is honest but curious,while the server may be trustless in the real world.Considering a malicious server not honestly performing the queries,verifiable SSE(VSSE)schemes are constructed to ensure the verifiability of the search results.However,existing VSSE constructions only focus on single-keyword search or incur heavy computational cost during verification.To address this challenge,we present an efficient VSSE scheme,built on OXT protocol(Cash et al.,CRYPTO 2013),for conjunctive keyword queries with sublinear search overhead.The proposed VSSE scheme is based on a privacy-preserving hash-based accumulator,by leveraging a well-established cryptographic primitive,Symmetric Hidden Vector Encryption(SHVE).Our VSSE scheme enables both correctness and completeness verifiability for the result without pairing operations,thus greatly reducing the computational cost in the verification process.Besides,the proposed VSSE scheme can still provide a proof when the search result is empty.Finally,the security analysis and experimental evaluation are given to demonstrate the security and practicality of the proposed scheme.展开更多
Cloud computing facilitates convenient and on-demand network access to a centralized pool of resources.Currently,many users prefer to outsource data to the cloud in order to mitigate the burden of local storage.Howeve...Cloud computing facilitates convenient and on-demand network access to a centralized pool of resources.Currently,many users prefer to outsource data to the cloud in order to mitigate the burden of local storage.However,storing sensitive data on remote servers poses privacy challenges and is currently a source of concern.SE(Searchable Encryption)is a positive way to protect users sensitive data,while preserving search ability on the server side.SE allows the server to search encrypted data without leaking information in plaintext data.The two main branches of SE are SSE(Searchable Symmetric Encryption)and PEKS(Public key Encryption with Keyword Search).SSE allows only private key holders to produce ciphertexts and to create trapdoors for search,whereas PEKS enables a number of users who know the public key to produce ciphertexts but allows only the private key holder to create trapdoors.This article surveys the two main techniques of SE:SSE and PEKS.Different SE schemes are categorized and compared in terms of functionality,efficiency,and security.Moreover,we point out some valuable directions for future work on SE schemes.展开更多
Recent attempts at key-aggregate searchable encryption(KASE) combine the advantages of searching encrypted data with support for data owners to share an aggregate searchable key with a user delegating search rights to...Recent attempts at key-aggregate searchable encryption(KASE) combine the advantages of searching encrypted data with support for data owners to share an aggregate searchable key with a user delegating search rights to a set of data. A user, in turn, is required to submit only one single aggregate trapdoor to the cloud to perform a keyword search across the shared set of data. However, the existing KASE methods do not support searching through data that are shared by multiple owners using a single aggregate trapdoor. Therefore, we propose a MULKASE method that allows a user to search across different data records owned by multiple users using a single trapdoor. In MULKASE, the size of the aggregate key is independent of the number of documents held by a data owner. The size of an aggregate key remains constant even though the number of outsourced ciphertexts goes beyond the predefined limit. Security analysis proves that MULKASE is secure against chosen message attacks and chosen keyword attacks. In addition, the security analysis confirms that MULKASE is secure against cross-pairing attacks and provides query privacy. Theoretical and empirical analyses show that MULKASE performs better than the existing KASE methods. We also illustrate how MULKASE can carry out federated searches.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.61932010 and 62072357)the Zhuhai Top Discipline-Information Securitysupported by the China Scholarship Council (CSC)and the Australian Research Council (ARC).
文摘Searchable symmetric encryption(SSE)has been introduced for secure outsourcing the encrypted database to cloud storage,while maintaining searchable features.Of various SSE schemes,most of them assume the server is honest but curious,while the server may be trustless in the real world.Considering a malicious server not honestly performing the queries,verifiable SSE(VSSE)schemes are constructed to ensure the verifiability of the search results.However,existing VSSE constructions only focus on single-keyword search or incur heavy computational cost during verification.To address this challenge,we present an efficient VSSE scheme,built on OXT protocol(Cash et al.,CRYPTO 2013),for conjunctive keyword queries with sublinear search overhead.The proposed VSSE scheme is based on a privacy-preserving hash-based accumulator,by leveraging a well-established cryptographic primitive,Symmetric Hidden Vector Encryption(SHVE).Our VSSE scheme enables both correctness and completeness verifiability for the result without pairing operations,thus greatly reducing the computational cost in the verification process.Besides,the proposed VSSE scheme can still provide a proof when the search result is empty.Finally,the security analysis and experimental evaluation are given to demonstrate the security and practicality of the proposed scheme.
基金This work is supported by Guangxi Cooperative Innovation Center of Cloud Computing and Big Data(No.YD16506)。
文摘Cloud computing facilitates convenient and on-demand network access to a centralized pool of resources.Currently,many users prefer to outsource data to the cloud in order to mitigate the burden of local storage.However,storing sensitive data on remote servers poses privacy challenges and is currently a source of concern.SE(Searchable Encryption)is a positive way to protect users sensitive data,while preserving search ability on the server side.SE allows the server to search encrypted data without leaking information in plaintext data.The two main branches of SE are SSE(Searchable Symmetric Encryption)and PEKS(Public key Encryption with Keyword Search).SSE allows only private key holders to produce ciphertexts and to create trapdoors for search,whereas PEKS enables a number of users who know the public key to produce ciphertexts but allows only the private key holder to create trapdoors.This article surveys the two main techniques of SE:SSE and PEKS.Different SE schemes are categorized and compared in terms of functionality,efficiency,and security.Moreover,we point out some valuable directions for future work on SE schemes.
文摘Recent attempts at key-aggregate searchable encryption(KASE) combine the advantages of searching encrypted data with support for data owners to share an aggregate searchable key with a user delegating search rights to a set of data. A user, in turn, is required to submit only one single aggregate trapdoor to the cloud to perform a keyword search across the shared set of data. However, the existing KASE methods do not support searching through data that are shared by multiple owners using a single aggregate trapdoor. Therefore, we propose a MULKASE method that allows a user to search across different data records owned by multiple users using a single trapdoor. In MULKASE, the size of the aggregate key is independent of the number of documents held by a data owner. The size of an aggregate key remains constant even though the number of outsourced ciphertexts goes beyond the predefined limit. Security analysis proves that MULKASE is secure against chosen message attacks and chosen keyword attacks. In addition, the security analysis confirms that MULKASE is secure against cross-pairing attacks and provides query privacy. Theoretical and empirical analyses show that MULKASE performs better than the existing KASE methods. We also illustrate how MULKASE can carry out federated searches.
