Sedigheh Khajouei-Nejad - North Tehran Branch, Islamic Azad University Tehran, Iran
Hamid Haj Seyyed Javadi - Shahed University Tehran, Iran
Sam Jabbehdari - North Tehran Branch, Islamic Azad University Tehran, Iran
Seyed Mohammad Hossein Moattar - Mashhad Branch, Islamic Azad University Mashhad, Iran

—In order to provide access control on encrypted data, Attribute-based encryption (ABE) defines each user using a set of attributes. Fuzzy identity-based encryption (FIBE) is a variant of ABE that allows for a threshold access structure for users. To address the potential threat posed by future quantum computers, this paper presents a postquantum fuzzy IBE scheme based on lattices. However, current lattice-based ABE schemes face challenges related to computational complexity and the length of ciphertext and keys. This paper aims to improve the performance of an existing fuzzy IBE scheme by reducing key length and computational complexity during the encryption phase. While negative attributes are not utilized in our scheme, we prove its security under the learning with error (LWE) hard problem assumption in the selective security model. These improvements have significant implications for the field of ABE.

Attribute-Based Encryption (ABE), Fuzzy Identity-Based Encryption (FIBE), policy, access structure, lattice, Learning with Errors (LWE)