An efficient private evaluation of a decision graph

Hiroki Sudo, Koji Nuida, Kana Shimizu

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    1 Citation (Scopus)


    A decision graph is a well-studied classifier and has been used to solve many real-world problems. We assumed a typical scenario between two parties in this study, in which one holds a decision graph and the other wants to know the class label of his/her query without disclosing the graph and query to the other. We propose a novel protocol for this scenario that can obliviously evaluate a graph that is designed by an efficient data structure called the graph level order unary degree sequence (GLOUDS). The time and communication complexities of this protocol are linear to the number of nodes in the graph and do not include any exponential factors. The experiment results revealed that the actual runtime and communication size were well concordant with theoretical complexities. Our method can process a graph with approximately 500 nodes in only 11 s on a standard laptop computer. We also compared the runtime of our method with that of previous methods and confirmed that it was one order of magnitude faster than the previous methods.

    Original languageEnglish
    Title of host publicationInformation Security and Cryptology – ICISC 2018 - 21st International Conference, Revised Selected Papers
    EditorsKwangsu Lee
    Number of pages18
    ISBN (Print)9783030121457
    Publication statusPublished - 2019 Jan 1
    Event21st International Conference on Information Security and Cryptology, ICISC 2018 - Seoul, Korea, Republic of
    Duration: 2018 Nov 282018 Nov 30

    Publication series

    NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
    Volume11396 LNCS
    ISSN (Print)0302-9743
    ISSN (Electronic)1611-3349


    Other21st International Conference on Information Security and Cryptology, ICISC 2018
    CountryKorea, Republic of


    • Decision graph
    • GLOUDS
    • Homomorphic encryption

    ASJC Scopus subject areas

    • Theoretical Computer Science
    • Computer Science(all)

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