International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Vincenzo Iovino

Publications

Year
Venue
Title
2020
PKC
Verifiable Inner Product Encryption Scheme 📺
In the standard setting of functional encryption (FE), we assume both the Central Authority (CA) and the encryptors to run their respective algorithms faithfully. Badrinarayanan et al. [ASIACRYPT 2016] proposed the concept of verifiable FE, which essentially guarantees that dishonest encryptors and authorities, even when colluding together, are not able to generate ciphertexts and tokens that give “inconsistent” results. They also provide a compiler turning any perfectly correct FE into a verifiable FE, but do not give efficient constructions. In this paper we improve on this situation by considering Inner-Product Encryption (IPE), which is a special case of functional encryption and a primitive that has attracted wide interest from both practitioners and researchers in the last decade. Specifically, we construct the first efficient verifiable IPE (VIPE) scheme according to the inner-product functionality of Katz, Sahai and Waters [EUROCRYPT 2008]. To instantiate the general construction of Badrinarayanan et al. we need to solve several additional challenges. In particular, we construct the first efficient perfectly correct IPE scheme. Our VIPE satisfies unconditional verifiability, whereas its privacy relies on the DLin assumption.
2016
PKC
2015
EPRINT
2015
EPRINT
2013
CRYPTO
2010
EPRINT
Fully Secure Anonymous HIBE and Secret-Key Anonymous IBE with Short Ciphertexts
Lewko and Waters [Eurocrypt 2010] presented a fully secure HIBE with short ciphertexts. In this paper we show how to modify their construction to achieve anonymity. We prove the security of our scheme under static (and generically secure) assumptions formulated in composite order bilinear groups. In addition, we present a fully secure Anonymous IBE in the secret-key setting. Secret-Key Anonymous IBE was implied by the work of [Shen-Shi-Waters - TCC 2009] which can be shown secure in the selective-id model. No previous fully secure construction of secret-key Anonymous IBE is known.