研究成果

国際会議

  • Information Theoretic Security for Encryption Based on Vonditional Rényi Entropies
    著者
    M. Iwamoto and J. Shikata
    会議名
    ICITS 2013
    LNSC 8317
    ページ
    101–121
    出版社
    Springer
    発行年
    2013
    Abstract

    In this paper, information theoretic cryptography is discussed based on conditional Rényi entropies. Our discussion focuses not only on cryptography but also on the definitions of conditional Rényi entropies and the related information theoretic inequalities. First, we revisit conditional Rényi entropies, and clarify what kind of properties are required and actually satisfied. Then, we propose security criteria based on Rényi entropies, which suggests us deep relations between (conditional) Rényi entropies and error probabilities by using several guessing strategies. Based on these results, unified proof of impossibility, namely, the lower bounds on key sizes are derived based on conditional Rényi entropies. Our model and lower bounds include the Shannon’s perfect secrecy, and the min-entropy based encryption presented by Dodis, and Alimomeni and Safavi-Naini at ICITS2012. Finally, a new optimal symmetric key encryption protocol achieving the lower bounds is proposed.