Ensuring reliable logging for data accountability in untrusted cloud storage

Data accountability can record and track data usage in cloud storage, in order to cope with users' fear of losing control of their own data or even data leakage. However, logs recording unauthorized data access could be omitted or falsified in untrusted cloud storage, which is the critical factor of unreliable data accountability. To address this problem, in this paper, we propose a novel Cloud Data Accountability Framework to ensure reliable logging for data accountability. In particular, we adopt programmable Java JAR file coupling with data to enclose access policy. This mechanism ensures that data access through JAR will trigger authentication and automated logging local to the JAR. To prevent data access without JAR and protect data from key abuse attack, we provide JAR-based Data Access Protocol. Extensive security and performance analysis makes comparison between our logging mechanism and the state-of-the-art. Results indicate that the proposed mechanism is more reliable and achieves space and time efficiency.