(Deterministic) hierarchical identity-based encryption from learning with rounding over small modulus

• Main Authors: FANG, Fuyang, LI, Bao, LU, Xianhui, LIU, Yamin, JIA, Dingding, XUE, Haiyang
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2016
• Subjects: (hierarchical) identity-based encryption; deterministic (hierarchical) identity-based encryption; learning with rounding; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/9181; https://ink.library.smu.edu.sg/context/sis_research/article/10186/viewcontent/2897845.2897922.pdf
• Institution: Singapore Management University

In this paper, we propose a hierarchical identity-based encryption (HIBE) scheme in the random oracle (RO) model based on the learning with rounding (LWR) problem over small modulus $q$. Compared with the previous HIBE schemes based on the learning with errors (LWE) problem, the ciphertext expansion ratio of our scheme can be decreased to 1/2. Then, we utilize the HIBE scheme to construct a deterministic hierarchical identity-based encryption (D-HIBE) scheme based on the LWR problem over small modulus. Finally, with the technique of binary tree encryption (BTE) we can construct HIBE and D-HIBE schemes in the standard model based on the LWR problem over small modulus.