Focusing on the fine-grained access control challenge of multi-user searchable encryption, we propose a hierarchical encryption scheme using blockchain-based indexing (HSE-BI). First, search index structure based DAG-type policy and stepwise key derivation mechanism; which outsourced to blockchain network achieve reliable search. We design dynamic append-only update protocol for deal with addin...

As so much advantage of cloud computing, more and more data owners centralize their sensitive data into the cloud. With a mass of data files stored in the cloud server, it is important to provide keyword based search service to data user. However, in order to protect the data privacy, sensitive data is usually encrypted before outsourced to the cloud server, which makes the search technologies ...

In this paper, we provide a secure and e cient encrypted keyword search scheme for multi-user data sharing. Specifically, a data owner outsources a set of encrypted files to an untrusted server, shares it with a set of users, and a user is allowed to search keywords in a subset of files that he is authorized to access. In the proposed scheme, (a) each user has a constant size secret key, (b) ea...

Searchable Public-Key Ciphertexts with Hidden Structures for keyword search is as fast as possible without sacrificing semantic security of the encrypted keywords. In SPCHS, all keyword-searchable ciphertexts are structured by hidden relations, and with the search trapdoor corresponding to a keyword, the minimum information of the relations is disclosed to a search algorithm as the guidance to ...

An encrypted email is sent from Bob to Alice. A gateway wants to check whether a certain keyword exists in an email or not for some reason (e.g. routing). Nevertheless Alice does not want the email to be decrypted by anyone except her including the gateway itself. This is a scenario where public key encryption with keyword search (PEKS) is needed. In this paper we construct a new scheme (KR-PEK...

Traditional approaches to secure computation begin by representing the function f being computed as a circuit. For any function f that depends on each of its inputs, this implies a protocol with complexity at least linear in the input size. In fact, linear running time is inherent for secure computation of non-trivial functions, since each party must “touch” every bit of their input lest inform...

In this paper we investigate the problem of protecting privacy for publishing search engine logs. Search engines play a crucial role in the navigation through the vastness of the Web. Privacy-preserving data publishing (PPDP) provides methods and tools for publishing useful information while preserving data privacy. Recently, PPDP has received considerable attention in research communities, and...

In this paper we examine the problem of defending privacy for publishing search engine logs. Search engines play a vital role in the navigation through the enormity of the Web. Privacy-preserving data publishing (PPDP) provides techniques and tools for publishing helpful information while preserving data privacy. Recently, PPDP has received significant attention in research communities, and sev...

To protect the privacy, sensitive information has to be encrypted before outsourcing to the cloud. Thus the effective data utilization becomes a significant challenge. Searchable encryption scheme has been developed to conduct retrieval over encrypted data. However, these schemes only support exact keyword search. Recent fuzzy search schemes mainly evaluate the similarity of keywords from the s...