Paper 2020/884

Leakage-Resilient Inner-Product Functional Encryption in the Bounded-Retrieval Model

Linru Zhang, Xiangning Wang, Yuechen Chen, and Siu-Ming Yiu

Abstract

We propose a leakage-resilient inner-product functional encryption scheme (IPFE) in the bounded-retrieval model (BRM). This is the first leakage-resilient functional encryption scheme in the BRM. In our leakage model, an adversary is allowed to obtain at most $l$-bit knowledge from each secret key. And our scheme can flexibly tolerate arbitrarily leakage bound $l$, by only increasing the size of secret keys, while keeping all other parts small and independent of $l$. Technically, we develop a new notion: Inner-product hash proof system (IP-HPS). IP-HPS is a variant of traditional hash proof systems. Its output of decapsulation is an inner-product value, instead of the encapsulated key. We propose an IP-HPS scheme under DDH-assumption. Then we show how to make an IP-HPS scheme to tolerate $l'$-bit leakage, and we can achieve arbitrary large $l'$ by only increasing the size of secret keys. Finally, we show how to build a leakage-resilient IPFE in the BRM with leakage bound $l=\frac{l'}{n}$ from our IP-HPS scheme.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Published elsewhere. Major revision. Will appear in ICICS 2020 proceedings
Keywords
Inner-Product Functional EncryptionBounded-Retrieval ModelHash Proof System
Contact author(s)
smyiu @ cs hku hk
History
2020-07-16: received
Short URL
https://ia.cr/2020/884
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2020/884,
      author = {Linru Zhang and Xiangning Wang and Yuechen Chen and Siu-Ming Yiu},
      title = {Leakage-Resilient Inner-Product Functional Encryption in the Bounded-Retrieval Model},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/884},
      year = {2020},
      url = {https://eprint.iacr.org/2020/884}
}
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