Data Security and Accountable Privacy in Cloud Computing Systems

云计算正在成为处理大规模、持久或广泛传播的数据的标准方法。因此，数据云已经成为计算领域的重要元素。随着数据云的重要性，我们开始看到将重要数据外包给第三方所带来的数据安全问题。

Cloud computing is becoming the standard way of computing with large-scale, long-lasting, or widely disseminated data. As a result, data clouds have become important elements of the computing landscape. With that importance of data clouds, we are beginning to witness the data safety problems that come with outsourcing important data to third parties. My research will address the data safety problems in two ways: (i) by limiting the opportunities for cloud servers to gain access to data and (ii) devising auditing facilities for users to check on the status of the spread of their data within the cloud system. I will investigate new ways of outsourcing computation to clouds while limiting the amount of information shared with them. Recently, secure outsourcing has become a hot topic in the context of cloud computing. However, the range of computations allowed after encrypting the data is a major issue. My research will use visual cryptographic techniques to develop encoding schemes that will allow comparisons of data values within clouds. By extending the types of computations that can be done while disguising the data, we can provide a framework that accommodates a wide range of cloud applications. In addition, I will investigate privacy auditing in data clouds. There is growing frustration among the users that large SaaS (software as a service) clouds (e.g., Facebook) are holding more information about their users than necessary. Also, users are concerned that data deletions and placement are not carried with the users' best interests (i.e., privacy) in mind. In the privacy auditing work I want to create a framework that will produce an independently created report on the spread of a user's information in the cloud. There are many interesting research challenges that should be addressed before realizing the above mentioned ways to data safety in clouds. Investigating and solving these challenges will be the focus of my research for next several years.