Selective Sharing of Outsourced Encrypted Data in Cloud Environments

Abstract

Owing to the vast volume of information gathered by computers, data protection and security has become a problem for organizations with the enormous rise in data transmission. Due to many advantages that cloud service providers provide, mainly economic benefits, several data owners outsource their data to cloud repositories. However, data owners do not have full ownership of the data after their data are outsourced. Thus, external data management systems are implemented to manage the data. Several kinds of research refer to the use of encryption techniques to prevent unauthorized access to data. Selective encryption aims at supporting selective and private access to outsourced data. However, the combination of this approach and indexing techniques cause confidentiality violations. In this article, a blockchain-based approach to data access is presented by implementing smart contracts over data access. These executable scripts bind users by stating access policies on the data. Furthermore, we provide a system, where users can offload their computational capabilities due to limitations in their computations. Our systems' computational capabilities outperform that of when users do the computation on their own. The results show a practical approach to data access management using blockchain technology.