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Fiat-Shamir Transformation

Paper: How to prove yourself

Description

Converts interactive identification and proof protocols into non-interactive ones by replacing the verifier's random challenge with a cryptographic hash of the prover's commitment. A fundamental technique used throughout modern ZKP systems. Relies on the Random Oracle Model (ROM).

Technical Characteristics

Complexity: - Prover: Same as interactive protocol + one hash evaluation - Verifier: Same as interactive protocol + one hash evaluation - Proof Size: Single-round (non-interactive) - Setup: transparent

Security: - Assumption: computational (Random Oracle Model) - Post-quantum: depends on underlying protocol and hash function - Basis: ROM, hardness of underlying interactive protocol

Dependencies

Based on: GMR85-Knowledge-Complexity, Sigma-Protocols-Damgard Circuit representation:

Applications

Used by: PLONK, Groth16, Bulletproofs, nearly all non-interactive ZKP systems

Resources