Research Area: Cloud Security
The widely applied cloud has brought the rapid increase in digital data. In spite that the internet services are widely adopted in the daily life, cloud clients take a great concern to security and privacy of their digital data because of losing the direct control of their data managed by the cloud server. Security and privacy become significant barriers to the spread of various internet technologies, such as cloud computing and cloud storage. To protect the data privacy, cloud clients can upload their data in the encrypted form. However, this creates a barrier for data classification and search operations. Testing if two ciphertexts contain the same plaintext is a promising approach to address the problem.
In this thesis, we propose a novel equality test scheme aiming to solve the problem of equality test over ciphertext. Our scheme adopts the identity-based approach to make the solution more practical. To further ensure the integrity of cloud data, which can be first encrypted using our identity-based encryption with equality test, we propose cryptographic protocols suitable for the novel PAYG payment model to address the problems of data integrity checking in the cloud. The first protocol is time encapsulated that ensures the original file can be retrived after successful auditing by a client. The second protocol is a privacy-preserving public auditing protocol that allows a third-party auditor (TPA) to audit outsourced data on behalf of its clients without sacrificing the data or the timestamp (i.e., time of storage). We also suggest a data integrity checking scheme to simultaneously check the data content and storage duration represented by an updatable timestamp with strong privacy against TPA.
Name of the Researcher: Tong Wu
Name of the Supervisor(s): Guomin Yang
Year of Completion: 2020
University: The University of Wollongong
Thesis Link: Home Page Url
