STAGE: Secure and Efficient Data Delivery for Exchange-Assisted Data Marketplaces

Cloud-based exchange-assisted data trading (EADT) has become the most important paradigm to trade data, where the exchange builds a bridge between data owners, brokers, and buyers to enable them to gain benefits from data, and cloud storage services serve as a key component to deliver data. With cloud-based EADT, the data can be traded in a customized way and the value of data can be unleashed as much as possible. Despite the great advantages of such a paradigm, critical issues also arise. The data content is confronted with leakage, leading to privacy violation. Conventional encryption can be utilized to resolve this tension, but it makes customized data trading inefficient and even impossible. In this paper, we propose a secure data delivery scheme, dubbed STAGE, for cloud-based EADT. STAGE supports customized data trading while freeing the broker from heavy costs in terms of computation and communication. We formally define the security notions of STAGE and prove that STAGE is secure against various attacks. We also implement a STAGE prototype and conduct a comprehensive performance evaluation to demonstrate its efficiency and practicality.