Logarithmic-Size Post-Quantum Linkable Ring Signatures Based on Aggregation Operations.

Area of Science:

• Cryptography
• Information Security
• Computer Science

Background:

• Linkable ring signatures balance signer anonymity with misuse prevention, crucial for cryptocurrencies and anonymous voting.
• Existing post-quantum schemes face challenges with large data sizes and complex circuits due to zero-knowledge proofs.

Purpose of the Study:

• To develop a logarithmic-size, post-quantum linkable ring signature scheme that overcomes the limitations of current methods.
• To enhance efficiency and reduce complexity in post-quantum cryptographic signature schemes.

Main Methods:

• A Merkle tree is constructed from ring members' public keys using a hash algorithm for logarithmic operations.
• A novel post-quantum aggregate signature scheme replaces complex zero-knowledge proof protocols.

Main Results:

• The proposed scheme meets correctness, anonymity, unforgeability, and linkability requirements for linkable ring signatures.
• The aggregation process ensures privacy by not revealing signing member information.
• Compared to Dilithium-based schemes, the new scheme shows dramatic improvements: 98.25% less signing time, 98.90% less verification time, and 99.81% smaller signature size for 1024 members.

Conclusions:

• The new scheme provides an efficient and secure post-quantum solution for linkable ring signatures.
• It effectively addresses the complexity and data size issues of previous post-quantum schemes.
• This advancement has significant implications for privacy-preserving applications in digital systems.