Group Oriented Attribute-Based Encryption Scheme from Lattices with the Employment of Shamir's Secret Sharing Scheme.

This paper delivers a post-quantum construction for group-oriented attribute-based encryption (GO-ABE) using lattice-based cryptography. The GO-ABE scheme enables users from the same group to combine their attributes to satisfy a decryption policy without revealing their secret keys. GO-ABE is particularly useful when no single user can fulfill the decryption policy alone, but a group of users can satisfy it together. Li et al. introduced the idea of GO-ABE at NSS 2015, discussing its importance in accessing patient data during emergencies. However, since Li et al.’s scheme uses bilinear mappings, it is not secure against quantum attacks. To ensure security against quantum attacks, we construct the GO-ABE scheme using the post-quantum cryptographic primitive lattices, and employ Shamir’s secret sharing scheme to meet the GO-ABE requirements.