Two-factor data security protection mechanism for cloud storage system

Joseph K. Liu, Kaitai Liang, Willy Susilo, Jianghua Liu, Yang Xiang

    Research output: Contribution to journalArticleResearchpeer-review

    70 Citations (Scopus)


    In this paper, 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.

    Original languageEnglish
    Article number7173024
    Pages (from-to)1992-2004
    Number of pages13
    JournalIEEE Transactions on Computers
    Issue number6
    Publication statusPublished - 1 Jun 2016


    • Cloud storage
    • Factor revocability
    • Security
    • Two-factor

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