Postquantum Zero-Knowledge in Constant Rounds

Explore the cutting-edge realm of postquantum zero-knowledge protocols in this 28-minute conference talk presented at the Association for Computing Machinery (ACM). Delve into the challenges of achieving zero-knowledge against quantum attackers and the importance of round complexity in these protocols. Examine the main focus on extractable commitments and the concept of quantumly-extractable classical commitments. Understand the limitations of traditional extraction techniques and the gap created by the no-cloning theorem in quantum mechanics. Learn about essential tools such as Quantum Fully-Homomorphic Encryption and Compute-and-Compare Obfuscation. Follow the progression of no-cloning extraction attempts, including the use of Circuit-Private FHE (SFE), and discover how researchers address issues like malleability to develop robust postquantum zero-knowledge protocols in constant rounds.

Intro
ZK against quantum attacks
The Round Complexity of ZK
Results
Main focus: Extractable Commitments
Quantumly-Extractable (Classical) Commitments
Traditional Extraction Techniques
The gap from classical techniques: Cloning No Cloning
Tools: Quantum Fully-Homomorphic Encryption
Tools: Compute-and-Compare (CC) Obfuscation
Simplification: Explainable Adversaries
st Try : No-Cloning Extraction
Tools: Circuit-Private FHE (SFE)
nd Try : No-Cloning Extraction
Problem: Malleability
rd (and last) Try: No-Cloning Extraction