Zero-Knowledge Arguments for Arithmetic Circuits Carsten Baum, - - PowerPoint PPT Presentation
Zero-Knowledge Arguments for Arithmetic Circuits Carsten Baum, - - PowerPoint PPT Presentation
Sub-Linear Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits Carsten Baum, Jonathan Bootle, Andrea Cerulli, Rafael del Pino, Jens Groth and Vadim Lyubashevsky Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits 2
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
Commitment/hash from SIS:
- Binding/collision resistant by SIS
- Hiding by Leftover Hash Lemma
- Homomorphic
- Compressing [A96]
3
=
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Prover Verifier Witness Statement
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Prover Verifier Witness Statement
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Prover Verifier Statement
Completeness: An honest prover convinces the verifier.
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Statement Prover Verifier
Soundness: A dishonest prover never convinces the verifier. Computational guarantee
- > argument
Completeness: An honest prover convinces the verifier.
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Statement Prover Verifier
Completeness: An honest prover convinces the verifier. Knowledge Soundness: The prover must know a witness to convince the verifier.
- > Proof/argument
- f knowledge
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Statement
Zero-knowledge: Nothing but the truth of the statement is revealed.
Prover Verifier
Completeness: An honest prover convinces the verifier.
Witness
Knowledge Soundness: The prover must know a witness to convince the verifier.
- > Proof/argument
- f knowledge
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Statement 3 Witness
Why arithmetic circuits?
- C to circuit compilers
- Models cryptographic
computations
- Witness existence? NP-Complete
Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits
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Prover Verifier
Prover Computation Verifier Computation Communication Cryptographic Assumption
Statement
Interaction
Results Table
Expected # Moves Communication Prover Complexity Verifier Complexity [DL12] [BKLP15] This Work
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Arithmetic Circuit Argument
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Arithmetic Circuits Matrix Equations Polynomials Commitments Protocol Extension Fields Proof of Knowledge Rejection Sampling
The interesting parts Featured in prior works DLOG Protocols Information Theoretic Proofs
Proof of Knowledge
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Statement Witness
Proof of Knowledge
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…
Typical Proofs of Knowledge
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Completeness: Knowledge Soundness:
Soundness Slack None for us*
Simplistic Protocol
P V
Rejection Sampling
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Our Protocol
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Our Protocol
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Proof-of-Knowledge Performance
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Expected # Moves Communication Prover Complexity Verifier Complexity [BDLN16] [CDXY17] This Work This Work
Arithmetic Circuit Argument
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Arithmetic Circuits Matrix Equations Polynomials Commitments Protocol Extension Fields Proof of Knowledge Rejection Sampling
High Level Structure
O + = = L R O
5 15 7 12 180
3 15 5 5 12 7 15
180
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High Level Structure
O + = = L R O
5 15 7 12 180
3 15 5 5 12 7 15
180
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High Level Structure
O
+
= = L R O
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High Level Structure
O
+
= = L R O
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Matrix Dimensions
~√N ~√N ~√N ~√N
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Paradigm from Previous Arguments
2 6 6 2 1 9 2 7 4 5 3 7 2 8 3 6 1 6 9 5 7 6 7 1 4 2 6 8 3 6 3 7 2 7 5 3 2 4 7 5 2 8 7 3 1 4 7 3
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Protocol Flow
P V
Check size bounds and linear combinations
, Proof of Knowledge
- 1. Commit to wire values
- 2. Commit to polynomial
coefficients
- 3. Commit to mod p
correction factors
- 4. Compute linear combinations, do
rejection sampling, proof of knowledge
Protocol Flow
P
√N
V
√N √N , Proof of Knowledge √N √N O(1) O(1)
Parameter Choice
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p, arithmetic circuits modulo p maximum size of honest prover committed values maximum size of openings from knowledge-extractor binding space for SIS commitments q, modulus for SIS Polynomial- sized gap
Additional Issues
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Not negligible! Negligible!
Schwarz-Zippel Lemma:
Empty Empty Rubbish Rubbish
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Thanks!
Expected # Moves Communication Prover Complexity Verifier Complexity
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- General Statements
- Sub-linear proofs
- Relies on SIS