Smooth Zero-Knowledge Hash Functions

TY - GEN

T1 - Smooth Zero-Knowledge Hash Functions

AU - Abdolmaleki, Behzad

AU - Khoshakhlagh, Hamidreza

AU - Lipmaa, Helger

N1 - Conference code: 22

PY - 2021

Y1 - 2021

N2 - We define smooth zero-knowledge hash functions (SZKHFs) as smooth projective hash functions (SPHFs) for which the completeness holds even when the language parameter lpar and the projection key hp were maliciously generated. We prove that blackbox SZKHF in the plain model is impossible even if lpar was honestly generated. We then define SZKHF in the registered public key (RPK) model, where both lpar and hp are possibly maliciously generated but accepted by an RPK server, and show that the CRS-model trapdoor SPHFs of Benhamouda et al. are also secure in the weaker RPK model. Then, we define and instantiate subversion-zero knowledge SZKHF in the plain model. In this case, both lpar and hp are completely untrusted, but one uses non-blackbox techniques in the security proof.

AB - We define smooth zero-knowledge hash functions (SZKHFs) as smooth projective hash functions (SPHFs) for which the completeness holds even when the language parameter lpar and the projection key hp were maliciously generated. We prove that blackbox SZKHF in the plain model is impossible even if lpar was honestly generated. We then define SZKHF in the registered public key (RPK) model, where both lpar and hp are possibly maliciously generated but accepted by an RPK server, and show that the CRS-model trapdoor SPHFs of Benhamouda et al. are also secure in the weaker RPK model. Then, we define and instantiate subversion-zero knowledge SZKHF in the plain model. In this case, both lpar and hp are completely untrusted, but one uses non-blackbox techniques in the security proof.

KW - Plain model

KW - RPK model

KW - SPHF

KW - Subversion zero-knowledge

KW - Trapdoor SPHF

UR - http://www.scopus.com/inward/record.url?scp=85121915437&partnerID=8YFLogxK

U2 - 10.1007/978-3-030-92518-5_23

DO - 10.1007/978-3-030-92518-5_23

M3 - Article in proceedings

SN - 978-3-030-92517-8

T3 - Lecture Notes in Computer Science

SP - 510

EP - 535

BT - Progress in Cryptology – INDOCRYPT 2021 - 22nd International Conference on Cryptology in India, 2021, Proceedings

A2 - Adhikari, Avishek

A2 - Küsters, Ralf

A2 - Preneel, Bart

PB - Springer

T2 - 22nd International Conference on Cryptology in India

Y2 - 13 December 2021 through 15 December 2021

ER -