Kyunghee Oh

Analysis and Countermeasure on Vulnerability of WPA Key Exchange Mechanism

In this paper, we analyze some weaknesses in WPA authenticator key management state machine and propose the countermeasures to overcome these problems. Our researches on IEEE 802.11i authenticator state machine that is WPA authenticator key management state machine reveal that the state machine cannot support the stable group key setting and is vulnerable to the replay attack and DoS attack. We describe 3 problems related to these vulnerabilities, propose the respective solutions and reconstruct WPA authenticator key management state machine to which the alternative solutions are applied.

A distributed file system over unreliable network storages

Nowadays, an individual uses multiple ICT devices such as PCs, laptops, smart phones and others. And the content files are not dedicated to a specific device, but shared by the devices. One of the sharing services is the personal cloud computing. Users can backup, synchronize, share and manage their files with it. But most cloud systems have their own dedicated interfaces and it is not easy to use files in various applications. We propose a distributed file system which works with the legacy internet protocols. Applications on devices can share files with the general file i/o interface, and our system enhanced reliability of file storages in both aspects of failures of servers and security risks.