Unified Authentication Framework

Unified Authentication Framework (UniAuth) streamlines all tasks in user authentication life cycles, which include tasks, such as creating accounts, authentication, updating passwords, and revocation of accounts. With UniAuth, people only need to carry one UniAuth device (such as their smartphones or wearable devices) to log into and manage their accounts securely for both online services and physical devices.

Crowd Resourcing

Crowd resourcing is an architecture that opportunistically leverages resources from passersby and their smartphones as components for ubiquitous systems. With Crowd Resourcing, we can use cheaper and simpler embedded nodes to build a variety of sophisticated ubiquitous systems, thus reducing deployment and management costs.

Wave to Me

We devleoped body-based identification system that leverages individual differences in body segment lengths and hand waving gesture patterns. Based on 2 seconds of hand-waving gestures captured by a Microsoft Kinect, the system identifies users around 98% accuracy.

CASA: Context-Aware Scalable Authentication

CASA is a way of balancing security and usability for authentication. Its core idea is to choose an appropriate form of active authentication (e.g., typing a PIN) based on the combination of multiple passive factors (e.g., a user’s current location) for authentication using a probabilistic framework.

Understanding Security in Real-World Contexts

To develop usable and secure systems, we need to understand how information security systems are used in real-world contexts. These works help researchers, practioners, and ourselves to make design choices about security systems.


TimeBlocks is a novel tangible, playful object to facilitate communication about concepts of time with young children. TimeBlocks consists of a set of cubic blocks that function as a physical progress bar. Parents and children can physically manipulate the blocks to represent the concept of time.


WebTicket is a low cost, easy-to-use and reliable web account management system that uses “tickets”, which are tokens that contain a two-dimensional barcode that can be printed or stored on smartphones. Users can log into accounts by presenting the barcodes to webcams connected to computers.


Undercover is an authenticaiton interface which uses multiple channels to prevent shoulder surfing attacks. Undercover conceals a part of challenge from a computer while many other shoulder-surfing resilient authentication schemes try to conceal resposes from users.

Use Your Illusion

Use your Illusion is a novel mechanism for user authentication that is secure and usable regardless of the size of the device on which it is used. The system relies on the human ability to recognize a degraded version of a previously seen image.

Laser Command

Laser Command is a game which I build using a 8x8 matrix LED and an Arduino Mini for a class. In Laser Command, we use a laser pointer as a two dimensional input device in conjunction with the 8x8 matrix LED.

Mobile Applications

Before starting my Ph.D., I've been developing many mobile applications for PalmOS for fun :)

Selected applications in English
All applications in Japanese