💻 computer science

BloQBench: A Blockchain Benchmarking Framework for Quantum Supremacy

The paper introduces BloQBench, a decentralized Ethereum-based framework that utilizes classically intractable puzzles with no pre-computed secrets to provide publicly verifiable, trustless assurance of quantum supremacy and automatically trigger transitions to quantum-secure cryptographic schemes upon successful demonstration.

Original authors: Nicholas J. C. Papadopoulos, Ramin Ayanzadeh

Published 2026-08-04

📖 7 min read🧠 Deep dive

CC BY 4.0

Original authors: Nicholas J. C. Papadopoulos, Ramin Ayanzadeh

Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine a world where computers are getting so powerful they can solve puzzles that would take a regular supercomputer longer than the age of the universe to crack. This is the exciting, slightly terrifying frontier of quantum computing. Think of a quantum computer not as a faster version of your laptop, but as a magical key that can instantly open locks that are designed to be unbreakable by normal means. The big question scientists are asking is: "How do we know for sure when a quantum computer has actually done this?"

Usually, when someone claims, "I did it!" they just say so, and we have to trust them. But in science, trust isn't enough; we need proof. The problem is that if a puzzle is too hard for a normal computer to solve, it's also too hard for a normal computer to check the answer. It's like asking someone to solve a maze in their head and then asking you to verify they didn't cheat, but you can't see the maze. This paper tackles that exact problem: How do we create a test that is impossible for a normal computer to fake, but easy to prove is real, without needing to trust the person who set the test?

The Digital Honeypot: BloQBench

The authors of this paper, Nicholas J.C. Papadopoulos and Ramin Ayanzadeh, have built a digital trap called BloQBench. Imagine a giant, public treasure chest sitting on a global network called a blockchain (think of it as a giant, unchangeable public ledger where everyone can see everything that happens). This chest is filled with money, but it's locked with 119 different, incredibly complex locks.

Here's the magic trick: No one, not even the person who built the chest, knows the combination to these locks. The locks are generated by a computer program (a "smart contract") that creates them on the spot using a method that ensures no "pre-computed secrets" exist. It's like a vending machine that randomly prints a unique, unsolvable riddle every time you press a button, and the machine itself forgets the answer immediately after printing it.

The challenge? The locks are based on integer factorization. In plain English, this means taking a massive, jumbled number and figuring out which two smaller prime numbers were multiplied together to create it. For a regular computer, this is like trying to un-bake a cake to find the exact eggs and flour used; it's practically impossible for big numbers. But for a quantum computer, using a special algorithm, it's like having a time machine that can see the ingredients before they were mixed.

The Game Plan: How It Works

The process is set up like a high-stakes game show with a twist:

The Setup: The smart contract generates 119 "locks." Each lock is a number made of 4,608 bits (a huge number). The contract is designed so that there is only a 1-in-a-billion chance that all of these locks could be solved by a regular computer. The goal is to make sure at least one of them is truly impossible for a normal computer to crack.
The Bounty: There is a pot of money (a "bounty") in the contract. The paper suggests a minimum of 800,000,000 gas (the currency used to pay for transactions on the Ethereum network) to cover the cost of solving the puzzles. If the current price is 23.8 Gwei per unit of gas, that's about 19.04 ETH.
The Race: Anyone can try to solve the locks. If you have a quantum computer (or a really lucky genius with a supercomputer), you can try to find the prime factors.
The Anti-Cheat: To stop people from stealing each other's answers, the system uses a "commit-reveal" scheme. You have to first lock your answer in a digital envelope (a hash) and wait one day. After that day, you open the envelope and show the answer. This prevents "front-running," where a bad actor sees your answer coming and steals it before you can claim the prize.
The Win: If you solve a lock, the contract marks it as "solved." If you solve the final, hardest lock, you get the entire bounty, and a giant flag on the blockchain flips to "TRUE." This flag is the undeniable proof that quantum supremacy has been achieved.

Why This Matters: The Automatic Switch

The coolest part of BloQBench isn't just the money; it's what happens when the flag flips. Currently, blockchains use "classical" security (like RSA and ECDSA) to protect your money. These are safe until a quantum computer comes along and breaks them.

The paper proposes that BloQBench acts as an automatic trigger. Imagine your bank account has a safety switch. As long as the "Quantum Flag" is false, the bank uses the fast, cheap, classical security. But the moment someone solves the puzzle and flips the flag to "TRUE," the system automatically switches to a new, "quantum-proof" security system (using something called Lamport signatures).

This is crucial because the new quantum-proof security is slower and more expensive to use. If we switch to it too early, we waste money and slow everything down. If we switch too late, our money gets stolen. BloQBench solves this by waiting for the exact moment the threat is proven real, then flipping the switch instantly.

What the Paper Rules Out

The authors were very careful about what they didn't do. They explicitly ruled out several other ideas:

No Trusted Generators: They rejected the idea of having a human or a company generate the puzzles. If a human makes the puzzle, they might keep a secret "backdoor" to solve it themselves, which ruins the proof.
No "Order-Finding": They considered a different type of math puzzle called "order-finding," but they found it was too expensive to set up on the blockchain (costing over 6 billion gas to deploy) compared to their factorization method (which cost about 237 million gas).
No Unverifiable Puzzles: They rejected "sampling problems" (where a computer generates random patterns) because, while hard to do, they are also hard to prove are correct. You can't easily check if the pattern is right, so it doesn't work as a public proof.

The Bottom Line

The paper doesn't claim that quantum computers have already beaten the world. Instead, it provides a framework and a tool (BloQBench) to prove it when they do. They have built the contract, tested it, and shown that it works. They calculated that solving one of their locks would cost about 6,110,290 gas for verification, and solving all 119 would cost about 741,048,802 gas.

The authors suggest that this system creates a "tunable gradient." You could make the locks easier to detect early signs of quantum power, or keep them super hard (like the 4,608-bit locks they chose) to wait for the moment when quantum computers can break the world's most famous encryption standards like RSA.

In short, BloQBench is a trustless, public, and automated referee. It waits for the quantum computer to step up to the plate, solves the puzzle, and then instantly flips the switch to protect our digital world, all without anyone needing to trust a single person. It turns the race for quantum supremacy into a game with a clear winner and a guaranteed safety net.

Technical Summary: BloQBench

Problem Statement
As quantum computing matures, verifying claims of "quantum supremacy" (the ability of a quantum computer to solve problems infeasible for classical computers) remains a critical challenge. Current verification methods often rely on trust-based assumptions or localized audits, lacking a universally agreed-upon, public standard. A fundamental bottleneck exists: if a workload is computationally intractable for classical hardware, verifying its solution is often equally intractable, making independent validation impossible. Furthermore, existing approaches to generating such workloads (e.g., integer factorization) typically require a trusted third party to generate the problem instance. This introduces a vulnerability where the generator could retain pre-computed secrets (e.g., the prime factors of a large number), allowing them to spoof a solution without ever executing a quantum workload. The community lacks a "trustless" mechanism to prove that a specific workload was executed on quantum hardware rather than classically spoofed.

Methodology
The authors propose BloQBench, a decentralized benchmarking framework implemented via an Ethereum smart contract. The core innovation is the generation of classically intractable puzzles directly on-chain without any pre-computed secrets or trusted generators.

Trustless Puzzle Generation: The framework utilizes the deterministic and public nature of Ethereum smart contracts. It employs a method based on Sander's technique to probabilistically generate "RSA-UFOs" (large integers that are difficult to factor) directly on the blockchain. Because all state transitions, random number generation (via on-chain pseudo-randomness), and execution paths are public, the contract cannot hide the prime factors used to create the puzzle. This eliminates the need for a trusted generator.
The Workload: The specific puzzle selected is integer factorization. The contract generates 119 "locks," each a 4,608-bit integer (composed of two 1,536-bit primes). The size is chosen to be infeasible for classical computers (with a confidence level of $10^{-9}$ that at least one lock cannot be factored classically) while remaining solvable by quantum hardware via Shor's algorithm.
Verification and Incentives: The framework uses a commit-reveal scheme with a one-day buffer to prevent front-running attacks. Solvers must first submit a hash of their solution (encrypted with their address) and wait 24 hours before revealing the actual prime factors. If the solution is correct (verified via Miller-Rabin primality tests and product verification), the lock is marked as solved.
Automated Triggers: The smart contract acts as a global, immutable ledger for verification. Upon the successful solving of the final lock, a public flag is set to "True." This flag serves as an automated trigger for external systems. As a proof-of-concept, the authors implemented an Ethereum account that monitors this flag. Before the flag is set, the account uses standard classical signature verification (ECDSA); once the flag is set, it automatically switches to a post-quantum signature scheme (Lamport signatures).
Economic Model: The contract accepts donations to fund a "bounty" (minimum 800,000,000 gas) to reimburse solvers for the computational costs of verification. The design allows the community to solve "easy" locks incrementally, leaving only the difficult, quantum-requiring locks for the final solver.

Key Contributions

A Tunable, Decentralized Benchmark Generator: A smart contract design capable of generating classically intractable puzzles without pre-computed secrets, providing a measurable gradient to track incremental milestones in quantum capabilities.
Trustless Verification Capability: The establishment of an unbiased, universally auditable framework for proving quantum supremacy milestones, leveraging the blockchain as a public ledger to eliminate the need for trusted third parties.
Automated Technological Transitions: A demonstration of how a verifiable benchmark can trigger system-level fallbacks to quantum-secure protocols, managing the trade-off between execution overhead and post-quantum security.
BloQBench Implementation: A working implementation using integer factorization and Lamport signatures, including cost analysis and security evaluations.

Results and Evaluation

Implementation: The authors successfully deployed the BloQBench contract on Ethereum using Solidity and Hardhat.
Cost Analysis:
- Deployment: Deploying the prime factorization contract with 119 locks (4,608 bits each) cost approximately 237,898,716 gas. This was significantly lower than the alternative "order-finding" approach, which cost over 6 billion gas for a similar setup.
- Verification: Verifying a single lock solution cost approximately 6,110,290 gas (dominated by the Miller-Rabin primality test). Solving all 119 locks (including those with known factorizations for testing) cost a total of 741,048,802 gas.
- Bounty: The authors recommend a minimum bounty of 800,000,000 gas to ensure solvers are reimbursed, with provisions for dynamic funding adjustments based on gas price fluctuations.
Security: The commit-reveal scheme with a one-day delay effectively mitigates front-running attacks. The authors demonstrate that an attacker would need to flood the mempool with high-fee transactions for an entire day to prevent a legitimate reveal, which is economically infeasible.
Comparison: The paper compares integer factorization against order-finding and other potential puzzles (e.g., sampling problems, proof-of-quantumness). Factorization was selected due to its lower deployment costs and the fact that it is a verifiable problem, unlike sampling problems which are often unverifiable.

Significance and Claims
The paper claims that BloQBench provides a novel, transparent, and automated metric for measuring quantum supremacy. By removing the reliance on trust-based verification, it offers a way to definitively settle debates regarding quantum advantage claims. The framework is significant because it:

Secures the Transition: It allows blockchain networks to maintain high-performance classical cryptography (avoiding the high gas costs of post-quantum schemes) until the exact moment quantum supremacy is cryptographically proven, at which point an automated switch to post-quantum security (like Lamport signatures) can occur.
Creates a Global Standard: It establishes a single, immutable historical record of when a specific quantum capability was proven, eliminating the latency between a claim and its verification.
Incentivizes Discovery: By combining reputational prestige with a financial bounty, the framework actively attracts advanced quantum systems to solve the puzzles.

The authors maintain a modest stance, noting that while BloQBench represents the "definitive" threshold (cryptographic quantum supremacy), future work could explore alternative workloads to detect earlier, weaker forms of quantum advantage. The core requirement remains that the benchmark must be classically verifiable and generated without hidden parameters.