Blockchain Designated Verifier Proofs Ensure Non-Transferable Privacy on Public Ledgers ∞ Research

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Briefing

Standard Designated Verifier Proofs (DVP) lose their crucial non-transferability property when recorded on a public blockchain, allowing third parties to verify the proof and compromising prover privacy. The Blockchain Designated Verifier Proof (BDVP) is introduced, a new cryptographic primitive that integrates a Chameleon Hash Function with a verifier-held trapdoor key. This mechanism grants the designated verifier the unique ability to computationally forge a simulated proof, rendering the proof non-negotiable. This breakthrough establishes a rigorous foundation for regulatory-compliant, privacy-preserving interactions on public ledgers, ensuring that proof validity remains confined to the intended verifier.

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Context

The core challenge in applying Designated Verifier Proofs (DVP) to public, immutable ledgers is the inherent conflict between non-transferability and public record. Traditional DVP schemes are designed to be verifiable only by a specific party, but when the proof transcript is broadcast and permanently stored, any third party can re-run the verification process if the verifier’s key is public. This action effectively makes the proof transferable, destroying the privacy guarantee of non-negotiability. This theoretical limitation has restricted the deployment of DVP in highly transparent, on-chain compliance and decentralized identity systems.

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Analysis

The BDVP scheme fundamentally alters the verifier’s role by making them a potential forger. The verifier is given a secret trapdoor key associated with a Chameleon Hash function. This trapdoor allows the verifier to find collisions in the hash function and use this capability to construct a proof that is mathematically indistinguishable from a genuine proof generated by the prover.

Conceptually, any third party observing the proof on the blockchain must assume it could have been forged by the verifier. This systematic ambiguity ∞ the inability of any third party to ascertain the proof’s origin ∞ is the mechanism that cryptographically enforces non-transferability and preserves the prover’s privacy on a public, immutable chain.

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Parameters

Non-Transferability Metric ∞ Enforced by the verifier’s ability to forge a proof, ensuring third parties cannot trust the proof’s origin.
Post-Quantum Security ∞ The BDVP scheme is constructed with a post-quantum solution, likely leveraging lattice-based cryptography, to resist future quantum attacks.
Core Cryptographic Tool ∞ Chameleon Hash Function, which allows for controlled collisions using a secret trapdoor.

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Outlook

This research opens new avenues for privacy-centric, regulatory-compliant decentralized applications. The BDVP primitive is a foundational building block for future on-chain identity and compliance protocols that require selective disclosure and proof non-negotiability, such as verifiable credentials for institutional DeFi. The inclusion of a post-quantum security solution positions this work as a critical component for the long-term resilience of cryptographic systems, anticipating the transition to quantum-safe blockchain architectures in the next three to five years.

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Verdict

The Blockchain Designated Verifier Proof is a fundamental cryptographic primitive that resolves the conflict between non-transferability and public record, securing the next generation of privacy-preserving on-chain systems.

Zero-knowledge proofs, designated verifier proof, non-transferability, privacy protection, public ledger, chameleon hash function, trapdoor key, post-quantum security, lattice-based cryptography, cryptographic primitive, verifiable computation, protocol design, security analysis, computational overhead, transaction privacy, identity management, proof simulation, quantum resistance, regulatory compliance, selective disclosure Signal Acquired from ∞ ieee.org