Zero-Knowledge Arguments for Arithmetic Circuits Carsten Baum, - - PowerPoint PPT Presentation

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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


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Sub-Linear Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits

Carsten Baum, Jonathan Bootle, Andrea Cerulli, Rafael del Pino, Jens Groth and Vadim Lyubashevsky

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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]

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=

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Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits

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Prover Verifier Witness Statement

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Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits

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Prover Verifier Witness Statement

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Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits

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Prover Verifier Statement

Completeness: An honest prover convinces the verifier.

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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.

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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
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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
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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
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Lattice-Based Zero-Knowledge Arguments for Arithmetic Circuits

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Prover Verifier

Prover Computation Verifier Computation Communication Cryptographic Assumption

Statement

Interaction

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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

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Proof of Knowledge

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Statement Witness

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Proof of Knowledge

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Typical Proofs of Knowledge

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Completeness: Knowledge Soundness:

Soundness Slack None for us*

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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

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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

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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

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

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Protocol Flow

P

√N

V

√N √N , Proof of Knowledge √N √N O(1) O(1)

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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

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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