日時： 平成27年11月27日 15時00分-17時00分
場所： 情報科学研究科 5階 コラボレーションルーム7
講演者氏名： Joseph Liu
講演題目： Two-Factor Data Security Protection Mechanism for Cloud Storage System
We propose a two-factor data security protection mechanism with factor
revocability for cloud storage system.
Our system allows a sender to send an encrypted message to a receiver
through a cloud storage server.
The sender only needs to know the identity of the receiver but no other
information (such as its public key or its
certificate). The receiver needs to possess two things in order to decrypt
the ciphertext. The first thing is his/her
secret key stored in the computer. The second thing is a unique personal
security device which connects to the
computer. It is impossible to decrypt the ciphertext without either piece.
More importantly, once the security device
is stolen or lost, this device is revoked. It cannot be used to decrypt any
ciphertext. This can be done by the cloud
server which will immediately execute some algorithms to change the existing
ciphertext to be un-decryptable by this device.
This process is completely transparent to the sender. Furthermore, the cloud
server cannot decrypt any ciphertext at any time.
The security and efficiency analysis show that our system is not only secure but also practical.