Chiemi Watanabe

Privacy-Preserving Queries for a DAS Model Using Encrypted Bloom Filter

Recently, Database-As-a-Service (DAS) has attracted considerable attention. Users require protecting sensitive data from the DAS administrators. Most of previous studies, which proposed the solutions using cryptographic techniques, assume that a large amount of data will be inserted into the database and new data will be uploaded infrequently. We propose a secure query execution model for such an environment. Our approach is to represent all schemes of each tuple in a plaintext table as one Bloom filter index, and to replace queries with keyword searches of the Bloom filter index. Same values in each tuple are transformed into different values by two-phase encryption. DAS administrators cannot determine the schemes of the original table even if they look view the database and queries. Therefore, our approach is robust against the estimation of schemes in original tables.

Query log perturbation method for privacy preserving query

Database as a Service (DaaS), a form of cloud computing, has recently attracted considerable attention. Users require their sensitive data to be protected from a database administrator that serves as a third party managing the data. We have proposed a secure query execution model for such an environment [10, 11]. Key features of our approach are to represent each tuple of each scheme as a plaintext table with one bloom filter index and to replace queries with keyword searches of the bloom filter index. In [12], we have defined an attack model in which attackers guess features of a plaintext table by observing bit patterns of the bloom filter index: further, we considered a defense against such as attack. We must also assume in this model that attackers can access query logs and may infer features of a plaintext table using such query logs. In this paper, we define an attack model by using query logs and propose a method to defend against the attack by executing fake queries.

Design and implementation of a multi-modal user interface of the Virtual World Database system (VWDB)

Reports on the design and implementation of a multi-modal user interface of the Virtual World Database (VWDB) system. VWDB is currently under development at Ochanomizu University with the aim of realizing a new-generation database system for cyberspace applications. The system is being constructed by integrating a virtual reality system and an object-oriented database system. Since VWDB provides a virtual world as the users database interface, the system must support a multi-modal database language with which users can interact with VWDB by means of gestures and voice. We introduce an automata-based approach to designing the multi-modal language. This idea is in response to the observation that an object in the virtual world changes its state according to a users query or an update request issued in a multi-modal manner. We identify a set of automata to characterize the multi-modal interaction and describe a semantic network approach for translating a multi-modal user input to an equivalent message to access and manipulate database objects.

SERPWatcher: A Sophisticated Mining Tool Utilizing Search Engine Results Pages (SERPs) for Social Change Discovery

As various individuals and organizations disseminate information on their Web pages, real-world social events and changes are considered to be reflected in Web trends. The billions of Web pages that now exist are retrieved by Web search engines which accept keywords and return a search engine results page (SERP). Since the SERP itself and the ranking order change with time reflecting the changes in society, it might be possible to accurately follow the movement of society by mining SERPs. This paper reports the design and implementation of a SERP mining tool named SERPWatcher. It provides sophisticated interfaces and functions for SERP miners in the field of social sciences to discover social changes. It could be a novel social survey method in that it totally differs from the traditional methods such as questionnaires and interviews. A research prototype of SERPWatcher is currently under operation, and its validation test shows that it has a fail-safe nature in the sense that social changes are mirrored on the changes of the SERP ranking order. Also, the testers conducting gender studies have been expressing positive opinions on the use of SERPWatcher as a novel research methodology in the field of sociology.

MWMD: a module-based workbench for multimedia database programmers and users

The recent proliferation of multimedia information has increased the need for quick support of newly developed media and technology by database management systems (DBMSs). Although an extensible DBMS based on object-oriented or object-relational database models has the capability to support user-defined functions, it is still a difficult task to incorporate a new algorithm developed in other fields into a specific DBMS, because the algorithm must be re-implemented with the server programming interface of the DBMS. With the purpose of making this task easier, we have built a system integrating an extensible DBMS, PostgreSQL, with a modular visualization environment (MVE), Khoros, which provides interactive visual programming environments and data processing libraries. In order to reduce the re-implementation overhead, our system translates a program developed for Khoros into the corresponding server-side function of PostgreSQL. Since MVEs are the de facto standard of visualization environments, new media-processing algorithms are expected to be developed in such environments. Our system makes these algorithms readily available for programmers and users of the DBMS. Moreover, the system provides the capability to formulate and execute SQL statements from the visual programming environment of Khoros. This feature also enables quick building of visual user-interfaces.

SERPWatcher: a SERP mining tool as a novel social survey method in sociology

Web search engines accept keywords and return a search engine results page (SERP). Since the SERP itself and the ranking order change with time reflecting the changes in society, it might be possible to accurately follow the movement of society by mining SERPs. This demonstration shows a SERP mining tool named SERPWatcher, which could be a novel social survey method in the field of sociology in that it totally differs from the traditional methods such as questionnaires and interviews.