New Quantum-Safe UPI Payment
Payment integrity secured by Quantum Walk Hash Function
Quantum Payment Chain
Chain Verification
Run verification or open this tab to load the chain.
⚠️ The Threat to Payment Systems
Today (SHA-256 Protected)
UPI, NEFT, and IMPS transactions are secured using SHA-256 hash functions. Each payment generates a unique fingerprint. Any tampering changes the fingerprint and is detected.
✅ Safe today
❌ Broken by quantum computers running Grover's Algorithm — effective security halved from 256-bit to 128-bit
Quantum Era Threat
A sufficiently powerful quantum computer can find SHA-256 collisions — two different payment amounts that produce the same hash. An attacker could modify ₹12,499 to ₹1,24,990 and produce a matching hash, making the tamper invisible to the payment gateway.
🚨 Payment fraud becomes undetectable
⚛️ How Quantum Walk Hash Functions Work
Sender + Receiver + Amount + Time
Each character → 8-bit ASCII
₹12,499 → 0011100101...
Walker evolves on 8×8 grid
Each bit steers the walk
U0 for '0', U1 for '1'
8×8 grid of probabilities
Highly sensitive to input
Chaotic, non-reversible
Matrix → integers → bits
Unique fingerprint
Quantum-resistant
The security of QHF comes from the chaotic sensitivity of quantum walks to initial conditions. A single bit change in the payment data steers the quantum walker down a completely different path, producing a hash that differs in approximately 50% of its bits. This avalanche property, proven in the paper's sensitivity analysis, means collision attacks are computationally infeasible even for quantum computers.
📄 Research Foundation
This implementation is based on:
Abd El-Latif, A.A., Abd-El-Atty, B., Mehmood, I., Muhammad, K., Venegas-Andraca, S.E., & Peng, J. (2021). Quantum-Inspired Blockchain-Based Cybersecurity: Securing Smart Edge Utilities in IoT-Based Smart Cities. Information Processing and Management, 58(3), 102549. https://doi.org/10.1016/j.ipm.2021.102549
The Controlled Alternate Quantum Walk (CAQW) mathematics implemented in this project — including the coin operators, shift operators, evolution operators, and hash generation formula — are taken directly from Section 3 of the above paper.
This project extends the paper's blockchain application to real-time UPI payment integrity verification.
Quantum Hash Function (CAQW-Based)
Based on Abd El-Latif et al., 2021 — Controlled Alternate Quantum Walks
Avalanche Effect Test
A 1-bit change in input should change ~50% of hash output
QHF vs SHA-256 — Avalanche Comparison
Both should change ~50% of bits on a 1-bit input flip.