TY - GEN
T1 - Unbounded Inner Product Functional Encryption from Bilinear Maps
AU - Tomida, Junichi
AU - Takashima, Katsuyuki
N1 - Publisher Copyright:
© 2018, International Association for Cryptologic Research.
PY - 2018
Y1 - 2018
N2 - Inner product functional encryption (IPFE), introduced by Abdalla et al. (PKC2015), is a kind of functional encryption supporting only inner product functionality. All previous IPFE schemes are bounded schemes, meaning that the vector length that can be handled in the scheme is fixed in the setup phase. In this paper, we propose the first unbounded IPFE schemes, in which we do not have to fix the lengths of vectors in the setup phase and can handle (a priori) unbounded polynomial lengths of vectors. Our first scheme is private-key based and fully function hiding. That is, secret keys hide the information of the associated function. Our second scheme is public-key based and provides adaptive security in the indistinguishability based security definition. Both our schemes are based on SXDH, which is a well-studied standard assumption, and secure in the standard model. Furthermore, our schemes are quite efficient, incurring an efficiency loss by only a small constant factor from previous bounded function hiding schemes.
AB - Inner product functional encryption (IPFE), introduced by Abdalla et al. (PKC2015), is a kind of functional encryption supporting only inner product functionality. All previous IPFE schemes are bounded schemes, meaning that the vector length that can be handled in the scheme is fixed in the setup phase. In this paper, we propose the first unbounded IPFE schemes, in which we do not have to fix the lengths of vectors in the setup phase and can handle (a priori) unbounded polynomial lengths of vectors. Our first scheme is private-key based and fully function hiding. That is, secret keys hide the information of the associated function. Our second scheme is public-key based and provides adaptive security in the indistinguishability based security definition. Both our schemes are based on SXDH, which is a well-studied standard assumption, and secure in the standard model. Furthermore, our schemes are quite efficient, incurring an efficiency loss by only a small constant factor from previous bounded function hiding schemes.
KW - Bilinear maps
KW - Function hiding
KW - Functional encryption
KW - Inner product
KW - Unbounded
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U2 - 10.1007/978-3-030-03329-3_21
DO - 10.1007/978-3-030-03329-3_21
M3 - Conference contribution
AN - SCOPUS:85057421107
SN - 9783030033286
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 609
EP - 639
BT - Advances in Cryptology – ASIACRYPT 2018 - 24th International Conference on the Theory and Application of Cryptology and Information Security, Proceedings
A2 - Peyrin, Thomas
A2 - Galbraith, Steven
PB - Springer Verlag
T2 - 24th Annual International Conference on Theory and Application of Cryptology and Information Security, ASIACRYPT 2018
Y2 - 2 December 2018 through 6 December 2018
ER -