Transparent Identity Verification Approach Using MPC and Efficient Credential Status Handling

A cost-effective, post-quantum secure eKYC framework with multidimensional bit-matrix compression and Layer-2 anchoring

Istiaque Ahmed; Shoji Kasahara; Kentaroh Toyoda; Tadashi Nakano; Thi Hong Tran· 2026· DOI 10.48550/arXiv.2609.14195

The core problem

Digital ecosystems require secure and privacy-preserving identity verification. Current eKYC frameworks relying on Zero-Knowledge Proofs (ZKPs) face high computational cost, rigid circuit design, complex integration, and expensive on-chain verification. The W3C 2021 BitString-based credential status mechanism also suffers from inefficient updates and poor scalability in large-scale deployments. To address these limitations, the authors propose a transparent and cost-effective identity verification framework based on Multi-Party Computation (MPC). The framework enables private off-chain code execution and produces runtime proofs anchored to a blockchain, aiming to deliver transparency, scalability, and quantum resistance for national-scale identity verification.

Experimental findings demonstrate the efficiency of the proposed framework. The ZSTD compression reduces credential data to 76 bytes, compared to 140 bytes with GZIP, achieving a reduction of approximately 45.7%. The system supports fine-grained status updates and Layer-2 blockchain anchoring, resulting in low-cost verification. Reusable verifiable presentations with unique access tokens enable cost-free verification for repeated use cases. Security studies validate robustness against quantum attacks due to SHA3 hashing and Falcon post-quantum signatures. The framework is shown to be scalable for national-scale identity verification.

Digital ecosystems require secure and privacy-preserving identity verification. Current eKYC frameworks relying on Zero-Knowledge Proofs (ZKPs) face high computational cost, rigid circuit design, complex integration, and expensive on-chain verification. The W3C 2021 BitString-based credential status mechanism also suffers from inefficient updates and poor scalability in large-scale deployments. To address these limitations, the authors propose a transparent and cost-effective identity verification framework based on Multi-Party Computation (MPC). The framework enables private off-chain code execution and produces runtime proofs anchored to a blockchain, aiming to deliver transparency, scalability, and quantum resistance for national-scale identity verification.

The proposed framework is built on Multi-Party Computation (MPC) for private off-chain code execution. It introduces a multidimensional bit-matrix model with efficient compression. Credential data is compressed using ZSTD, reducing the size to 76 bytes compared to 140 bytes with GZIP, thereby cutting storage and bandwidth costs. The system supports fine-grained status updates and Layer-2 blockchain anchoring for tamper-evident, low-cost verification. It employs reusable verifiable presentations (VPs) with unique access tokens, enabling cost-free verification and stronger access control. Selective disclosure preserves user control and strengthens privacy. Finally, the system integrates SHA3 hashing and Falcon post-quantum signatures to guarantee robustness against quantum attacks.

The MPC-based approach addresses the high computational cost and rigidity of ZKP-based eKYC by moving computation off-chain while maintaining transparency through blockchain anchoring. The multidimensional bit-matrix model with ZSTD compression significantly reduces storage and bandwidth requirements, making it suitable for large-scale deployments. Fine-grained status updates overcome the inefficiencies of W3C BitString-based mechanisms. Layer-2 anchoring provides tamper-evident verification at low cost. The use of reusable VPs with access tokens enhances access control and eliminates verification costs. Selective disclosure ensures user privacy and control. The integration of SHA3 and Falcon signatures future-proofs the system against quantum attacks. Overall, the framework offers a transparent, cost-effective, and scalable solution for national-scale identity verification, as validated by experimental and security analyses.

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