As researchers in quantum computing celebrate significant advancements, Web3’s asset base, valued at $4 trillion, is confronted with a critical challenge. Last December, Google revealed that their quantum Willow chip executed a computation in under five minutes—something that would require a top-tier supercomputer ten septillion years (approximately 100 trillion times the age of our universe) to accomplish. Fields like drug discovery, materials science, financial modeling, and optimization will thrive in this new era of quantum computing. However, current encryption methods, which depend on complex mathematical puzzles that classical computers find insurmountable, may be easily compromised by quantum technology.
In the realm of Web3, adversaries are proactively gathering encrypted blockchain data to exploit in the future as quantum capabilities advance. Investing in cryptocurrency is fundamentally tied to the security of cryptography, a domain directly challenged by quantum developments.
On a positive note, researchers are showing that innovative zero-knowledge (ZK) cryptography can fortify the leading blockchains against quantum threats, enabling Web3 to harness quantum-related advancements—from revolutionary antibiotics to highly efficient supply chains—while safeguarding it from associated risks.
The quantum edge
On October 22, Google published verifiable findings in Nature, confirming that its quantum chip is “effective in understanding the structure of natural systems, from molecules to magnets to black holes, [operating] 13,000 times faster than the most advanced classical algorithm on one of the world’s fastest supercomputers.” These findings are particularly remarkable as they are based on practical issues with real scientific implications rather than artificial benchmarks.
Despite the immense potential of quantum to expand human understanding, it undeniably threatens cryptography overall and the nearly $4 trillion digital asset market specifically. The Human Rights Foundation released a report indicating that over six million BTC are held in early “quantum vulnerable” account types, including Satoshi’s untouched 1.1 million BTC. These accounts might become early victims on “Q Day” (the day quantum computing can effectively breach public-key encryption).
Both Ethereum and Bitcoin utilize the Elliptic Curve Digital Signature Algorithm (ECDSA), which is notably susceptible to “Shor’s algorithm,” a quantum algorithm formulated in the 1990s specifically for efficiently determining the prime factors of large integers—a task that’s otherwise impractical for classical machines. There is even a theoretical possibility that quantum computing has already compromised Bitcoin, though we may not be fully aware of it yet.
Nevertheless, some experts have dismissed the gravity of the threat. Jameson Lopp, recognized in cypherpunk circles, noted on X that “the fear and uncertainty around quantum computing might pose a greater risk than quantum itself.” Essentially, he implies that our only adversary is fear. Regardless, across the board, experts agree the quantum risk is significant. Vitalik Buterin assesses the likelihood of quantum compromising Ethereum at 20% by 2030, emphasizing the need for readiness.
The urgency of the timeline cannot be overstated. Employing a strategy of collecting encrypted data now for decryption later accelerates the timeline considerably. Potential threats (including nation-states and hacker collectives) are stockpiling blockchain data—ranging from wallet backups to exchange custody files—to exploit once quantum technology matures. Each transaction sent to the network, every public key exposed, becomes potential ammunition for future attacks. The opportunity to implement quantum-resistant cryptography diminishes with each quarter that passes.
Introducing zero-knowledge
The elegance and simplicity of zero-knowledge (ZK) cryptography is its main strength. A prover can demonstrate the truth of a statement to a verifier without divulging any details apart from its validity. As ZK technology evolves, proof times have reduced from hours to seconds, and proof sizes have shrunk from megabytes to kilobytes. However, the computational demands of AI remain high, restricting its applicability to high-stakes domains such as Web3, traditional banking, and defense.
Zero-knowledge and quantum
At first glance, it may not be immediately clear how zero-knowledge technology can shield blockchains from quantum threats. Zero-knowledge proofs act as privacy mechanisms, allowing validation without the exposure of underlying information. However, these same privacy-preserving strategies can be built on quantum-resistant mathematical structures, effectively turning ZK into a comprehensive defense for blockchains. Hash-based proofs (employing zk-STARKs) and lattice-based proofs, which are based on problems that even advanced quantum machines struggle with, do not depend on quantum-vulnerable elliptic curves.
That said, quantum-resistant ZK proofs are typically larger and more complex than current models. This increase complicates their storage and raises verification costs on space-constrained blockchains. However, the payoff is substantial: they provide a mechanism to safeguard billions of on-chain assets without necessitating an immediate and risky overhaul of the foundational protocol.
In essence, ZK affords blockchains a flexible route for upgrades. Instead of completely overhauling their signature frameworks overnight, networks could gradually integrate quantum-safe ZK proofs into transactions, facilitating a coexistence between old and new cryptographic methods during the transition.
The quantum advantage for Web3
Current computing systems can only generate pseudo-randomness. They rely on algorithms to produce “random” numbers, which ultimately arise from predictable processes. This predictability can allow parts of a blockchain system—like the selection of validators for the next block or determining winners in decentralized lotteries—to be subtly manipulated for the financial advantage of malicious actors. However, earlier this year, quantum researchers reached a significant milestone: certified randomness.
Quantum systems tap into natural, unpredictable events like photon spins or particle decay. This results in genuine, unforgeable randomness that classical systems cannot achieve.
This development holds considerable implications for blockchains. The Web3 landscape necessitates a public, quantum-enhanced randomness beacon to underpin the essential operations of blockchains. With quantum technology, we can create one that is equitable, tamper-proof, and immune to manipulation, effectively resolving long-standing issues in decentralized lotteries and validator selection.
The pressing question remains: Will Web3 prioritize quantum-resistant cryptography before quantum computation reaches maturity? Historical trends indicate that upgrades to the foundational layers of major blockchain protocols often span years, largely due to the inherent lack of centralized coordination in decentralized frameworks. Nonetheless, the industry cannot afford to wait for quantum advancements to compromise ECDSA before initiating action.
The specifics of the timeline may be debated, but a quantum future is an undeniable reality on the horizon. ZK can safeguard Web3 amid this shift, transforming quantum challenges into quantum possibilities.
Immediate action is essential, while we still possess the means.
