## Cryptology ePrint Archive: Report 2019/051

Deterministic Identity-Based Encryption from Lattice-Based Programmable Hash Functions with High Min-Entropy

Daode Zhang and Jie Li and Bao Li and Xianhui Lu and Haiyang Xue and Dingding Jia and Yamin Liu

Abstract: There only exists one deterministic identity-based encryption (DIBE) scheme which is adaptively secure in the auxiliary-input setting, under the learning with errors (LWE) assumption. However, the master public key consists of $\mathcal{O}(\lambda)$ basic matrices. In this paper, we consider to construct adaptively secure DIBE schemes with more compact public parameters from the LWE problem. On the one hand, we gave a generic DIBE construction from lattice-based programmable hash functions with high min-entropy. On the other hand, when instantiating our generic DIBE construction with four LPHFs with high min-entropy, we can get four adaptively secure DIBE schemes with more compact public parameters. In one of our DIBE schemes, the master public key only consists of $\omega(\log \lambda)$ basic matrices.

Category / Keywords: public-key cryptography / deterministic identity-based encryption, adaptively secure, auxiliary-input, compact public parameters, the learning with errors, lattice-based programmable hash functions with high min-entropy

Original Publication (with minor differences): SCN 2019