1. 1 Design of Key-Sharing System Based on a Unique Device Kenji Imamoto (Kyushu Univ.) Hiromi Fukaya (Pastel) Kouichi Sakurai (Kyushu Univ.)

2. 2 Background In these days, a lot of services using the internet (e.g. e-commerce, banking, e-government) has been developed There exists several ways for securing communication - Password, Biometrics, IC card, … How to Realize Device-Authentication – Confirm whether it is a correct equipment by using a peculiar value of the equipment Our research is

3. 3 IST scheme ID-based encryption scheme based on Symmetric-key technique with a Trusted device –Introduce unique device Each device has an unforgeable area that stores unique ID (ie. cloning of the device is assumed to be impossible) Name Plaintext Ciphertext

4. 4 Conclusion Design a key-sharing system for device authentication based on unique-device –Cloning of a device is prohibited due to TR-HW with unique ID Future Work –Design an algorithm for generating secret key and unique ID How to reduce the damage of whole system when a device is broken –Investigate the limitation of system using unique-device –Concrete implementation and application