New Constructions of Identity-Based Dual Receiver Encryption from Lattices

Area of Science:

• Cryptography
• Computer Science
• Information Security

Background:

• Dual Receiver Encryption (DRE) allows a ciphertext to be decrypted by two different receivers to the same plaintext.
• Identity-Based DRE (IB-DRE) combines DRE with identity-based encryption (IBE), offering practical applications.
• Existing IB-DRE schemes often rely on bilinear pairings vulnerable to quantum attacks.

Purpose of the Study:

• To develop a post-quantum secure IB-DRE scheme based on lattice cryptography.
• To improve the efficiency of lattice-based IB-DRE, specifically by reducing the size of public parameters.
• To extend the proposed scheme to a hierarchical setting and ensure its security.

Main Methods:

• Introduced an injective map and a homomorphic computation technique.
• Constructed a novel lattice-based IB-DRE scheme with reduced public parameter size.
• Extended the scheme to a hierarchical IB-DRE (HIB-DRE) and proved security.

Main Results:

• The proposed lattice-based IB-DRE scheme uses significantly smaller public parameters (e.g., 12% of prior work for specific parameters).
• A flexible constant 'p' allows for adjustable efficiency and security trade-offs.
• The scheme is proven to be indistinguishable against adaptively chosen identity and plaintext attacks (IND-ID-CPA).

Conclusions:

• The developed lattice-based IB-DRE scheme offers a more efficient and quantum-resistant alternative.
• The hierarchical extension addresses scalability and key management challenges.
• The proven security guarantees the scheme's robustness for practical applications.