Cryptology ePrint Archive: Report 2018/833

Improved Inner-product Encryption with Adaptive Security and Full Attribute-hiding

Jie Chen and Junqing Gong and Hoeteck Wee

Abstract: In this work, we propose two IPE schemes achieving both adaptive security and full attribute-hiding in the prime-order bilinear group, which improve upon the unique existing result satisfying both features from Okamoto and Takashima [Eurocrypt '12] in terms of efficiency.

- Our first IPE scheme is based on the standard $k$-Lin assumption and has shorter master public key and shorter secret keys than Okamoto and Takashima's IPE under weaker DLIN=$2$-lin assumption.

- Our second IPE scheme is adapted from the first one; the security is based on the XDLIN assumption (as Okamoto and Takashima's IPE) but now it also enjoys shorter ciphertexts.

Technically, instead of starting from composite-order IPE and applying existing transformation, we start from an IPE scheme in a very restricted setting but already in the prime-order group, and then gradually upgrade it to our full-fledged IPE scheme. This method allows us to integrate Chen et al.'s framework [Eurocrypt '15] with recent new techniques [TCC '17, Eurocrypt '18] in an optimized way.

Category / Keywords: public-key cryptography /

Original Publication (with minor differences): IACR-ASIACRYPT-2018

Date: received 5 Sep 2018, last revised 5 Sep 2018

Contact author: s080001 at e ntu edu sg; junqing gong at ens-lyon fr; wee at di ens fr

Available format(s): PDF | BibTeX Citation

Version: 20180906:200622 (All versions of this report)

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