Data outsourcing services have emerged with the increasing use of digital information. They can be used to store data from various devices via networks that are easy to access. Unlike existing removable storage systems, storage outsourcing is available to many users because it has no storage limit and does not require a local storage medium. However, the reliability of storage outsourcing has b...

Asymmetric searchable encryption allows searches to be carried over ciphertexts, through delegation, and by means of trapdoors issued by the owner of the data. Public Key Encryption with Keyword Search (PEKS) is a primitive with such functionality that provides delegation of exact-match searches. As it is important that ciphertexts preserve data privacy, it is also important that trapdoors do n...

Free cloud-based services are powerful candidates for deploying ubiquitous encryption for messaging. In the case of email and increasingly chat, users expect the ability to store and search their messages persistently. Using data from one of the top three mail providers, we confirm that for a searchable encryption scheme to scale to millions of users, it should be highly IO-efficient (locality)...

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...

Fine-grained public key encryption with keyword search (PEKS), allowing users to on encrypted data flexible access control policy, has been widely studied recently due its promising application real-world scenarios such as cloud computing. However, most of the existing fine-grained PEKS schemes are either only able support single (e.g., attribute-based control) or susceptible being attacked com...

Processing queries on encrypted data protects sensitive data stored in cloud databases. CryptDB has introduced the approach of adjustable encryption for such processing. A database column is adjusted to the necessary level of encryption, e.g. order-preserving, for the set of executed queries, but never reversed. This has the drawback that long running cloud databases will eventually transform i...

The advent of cloud computing offers clients with the opportunity to outsource storage and processing of large volumes of shared data to third party service providers, thereby enhancing overall accessibility and operational productivity. However, security concerns arising from the threat of insider and external attacks often require the data to be stored in an encrypted manner. Secure and effic...

Searchable encryption has received a signi cant attention from the research community with various constructions being proposed, each achieving asymptotically optimal complexity for speci c metrics (e.g., search, update). Despite their elegancy, the recent attacks and deployment e orts have shown that the optimal asymptotic complexity might not always imply practical performance, especially if ...