Author: Callum Reid, CoinTelegraph; Translated by: Deng Tong, Golden Finance
1. What is Google’s Willow quantum chip?
Google's Willow chip marks a new era of quantum performance, enabling complex calculations with major implications for a variety of industries, including cryptography.
Quantum computing has reached a major milestone with the launch of Google’s 105-qubit Willow chip, built on the company’s breakthrough Sycamore processor.
Willow Overview:
105 qubits: Willow nearly doubles Sycamore’s qubit count, unlocking the ability to handle exponentially more complex calculations. Each qubit in Willow is designed to operate with improved coherence time, minimizing quantum noise and enhancing computational stability.
Error Correction Breakthrough: One of Willow's most notable advances is its progress in quantum error correction, a key step toward scalable, fault-tolerant quantum systems. Researchers at Google reported that Willow achieved longer logical qubit lifetimes than physical qubits, demonstrating its potential for sustained performance.
Speed and power: In benchmarks such as random circuit sampling, a test in which quantum computers demonstrate their capabilities by solving complex problems, Willow completed in minutes what would take a conventional supercomputer billions of years. These breakthroughs highlight the chip’s ability to outperform classical systems in specific problem domains.
2. Quantum Computing and Classical Computing
The fundamental difference between quantum computing and classical computing lies in the way information is processed.
Let's look at these differences in more detail:
Classical computing: performs calculations sequentially using binary bits (0s and 1s). Even the fastest classical supercomputers can solve problems using a linear series.
Quantum computing: uses qubits, which can exist in a superposition state (0 and 1 at the same time). When qubits are entangled, they affect each other instantly, enabling the system to process multiple calculations in parallel.
This parallelism enables quantum computers to excel at specialized tasks such as optimization problems, molecular simulations, and cryptographic testing, where classical systems fare poorly due to their linear constraints.
Real-world examples of Willow's computing power:
Drug Discovery and Materials Science: Willow's ability to simulate quantum states enables researchers to study complex molecular interactions. For example, simulating protein folding, a computationally intensive task, can be performed more efficiently using quantum systems.
Climate Modeling: By solving nonlinear equations at quantum speeds, Willow can model complex environmental systems, providing insights into climate change mitigation strategies.
Optimization problems: Willow’s capabilities extend to solving logistics challenges such as supply chain optimization and financial modeling, significantly reducing solution time compared to traditional approaches.
Willow’s debut not only highlights the progress of quantum computing, but also its potential to solve challenges previously thought insurmountable.
3. How can quantum computers theoretically crack cryptographic algorithms?
Quantum computers using algorithms such as Shor and Grover have the potential to solve complex problems exponentially faster, breaking traditional encryption algorithms.
The launch of powerful quantum computers like Willow has raised concerns about their impact on cryptographic security, including the impact of the Willow chip on cryptocurrencies. Bitcoin and many other blockchain systems rely on cryptographic algorithms designed to resist classical attacks. However, quantum computing has raised concerns about its potential impact on cryptographic security.
The Importance of Public and Private Keys in Bitcoin Security
Bitcoin's security is built on elliptic curve cryptography (ECC), specifically the Elliptic Curve Digital Signature Algorithm (ECDSA), which has raised concerns about quantum chips and digital signatures. The relationship between public and private keys is crucial:
Public key: Shared publicly as the address for receiving Bitcoins.
Private Key: Keeps secret and is used to sign transactions, prove ownership, and authorize the movement of funds.
The security premise behind ECDSA is the Elliptic Curve Discrete Logarithm Problem (ECDLP), which is computationally unsolvable for classical computers. Without access to the user's private key, it is nearly impossible to forge a valid signature or obtain funds.
How quantum algorithms threaten cryptography
However, quantum computers could undermine this security framework. Two key quantum algorithms highlight the risks:
Shor's algorithm: Cryptographic systems such as ECC can be cracked by quickly solving problems such as integer factorization, allowing the private key to be derived from the public key.
Grover's algorithm: Provides a quadratic speedup for brute-forcing hash functions. In the case of Bitcoin, this reduces the effective strength of SHA-256 (used for proof-of-work consensus) from 256 bits to 128 bits. While this is still secure by today's standards, it highlights potential vulnerabilities in other systems with weaker hash functions.
The quantum energy needed to crack Bitcoin
Breaking Bitcoin’s cryptographic defenses is far beyond the capabilities of today’s quantum computers, including Willow. According to research published in the Ledger Journal:
Required logical qubits: At least 1,500-3,000 fault-tolerant logical qubits are required to run Shor's algorithm efficiently.
Physical qubits required: Given current error rates, this amounts to tens of millions of physical qubits for error correction.
As Alan Watts has emphasized, today’s systems are still in the “noisy intermediate-scale quantum” (NISQ) phase (a term coined by American theoretical physicist John Preskill), where errors and instabilities limit their practical applications.
4. Bitcoin’s Current Defense Mechanism
Bitcoin's security relies on advanced cryptographic algorithms designed to resist classical attacks, ensuring strong protection of transactions and the blockchain network.
Bitcoin's cryptographic design makes it one of the most secure decentralized systems. Its defenses rely on powerful algorithms that are computationally unbreakable using classical computing. Let's look at the key safeguards and whether Google's Willow quantum chip poses any credible threat to them.
ECDSA and SHA-256: The Core of Bitcoin Security
As mentioned above, Bitcoin's transaction system relies on ECDSA to generate and verify digital signatures. In addition, Bitcoin's PoW consensus mechanism uses SHA-256 (a cryptographic hash function) to protect the blockchain:
Miners solve computational puzzles involving SHA-256 to add new blocks to the blockchain.
Hash functions are designed to be irreversible, meaning that it is computationally infeasible to reverse engineer the input data from its hash output.
Is Willow a threat to Bitcoin?
Although Google's Willow quantum chip marks a major milestone in quantum computing with its 105 qubits, it does not currently pose a direct threat to Bitcoin's cryptographic system. Cracking Bitcoin's ECDSA or SHA-256 would require at least 1,500-3,000 fault-tolerant logical qubits, far beyond Willow's capabilities. As mentioned earlier, the scalability of current quantum systems is not yet sufficient to challenge Bitcoin's strong defenses.
Bitcoin’s layered cryptographic structure combines ECDSA and SHA-256, ensuring resistance to today’s quantum technologies. You can think of Willow as a NISQ phase, where errors and instabilities limit their practical use. This technological gap currently keeps Bitcoin’s cryptographic protections secure.
5. Responses from the crypto community and cryptographers on whether Willow threatens Bitcoin security
Recognizing the eventual threat posed by quantum computing, the cryptocurrency industry has actively begun researching and developing quantum-resistant cryptographic systems.
Ongoing Efforts in Post-Quantum Cryptography
The National Institute of Standards and Technology (NIST) has been leading the standardization effort for post-quantum cryptography (PQC) algorithms. These algorithms are designed to resist both classical and quantum attacks. The final candidates include:
Lattice-based cryptography: Algorithms like CRYSTALS-Dilithium and Kyber rely on lattice structures that are secure against quantum attacks.
Hash-based signatures: These signatures use cryptographic hashes and are more resistant to quantum algorithms such as Shor or Grover.
Once finalized, these standards could be integrated into Bitcoin and other blockchain systems to ensure their security.
Vitalik Buterin's suggestions for Ethereum security
Ethereum co-founder Vitalik Buterin has been outspoken about the need to prepare for quantum risks. Key recommendations include:
Lamport signature: A quantum-resistant one-time signature scheme that is easy to implement but requires more storage space.
Transition flexibility: Ethereum’s modular structure enables it to adopt new cryptographic standards faster than Bitcoin. For example, Ethereum can integrate post-quantum algorithms by updating its consensus mechanism.
Buterin’s proactive approach provides a blueprint for other blockchain projects.
Wider industry research
Prominent cryptographers and researchers are contributing to the development of quantum-resistant technologies:
Adam Back: A pioneer in blockchain cryptography, Back stressed the importance of integrating PQC (post-quantum cryptography) into the Bitcoin protocol without compromising its decentralized nature.
Bill Buchanan: His work on lattice-based cryptography and security systems provides powerful solutions for defending against quantum attacks.
Many blockchain projects are also exploring hybrid models that combine existing cryptography with quantum-resistant algorithms to ensure a smooth transition when quantum computers become practical.
What’s at stake: the potential impact of quantum breakthroughs
Quantum breakthroughs could impact blockchain security, posing risks of compromised wallets and market instability, while driving advances in cryptographic defenses.
The rise of quantum computing presents both quantum computing risks and opportunities for Bitcoin and the broader cryptocurrency ecosystem. Understanding these impacts is critical for stakeholders.
Potential risks
Wallet damage:
A fully scalable, fault-tolerant quantum computer could derive the private key from the public key, enabling unauthorized access to a wallet.
If this happens, funds could be stolen, undermining trust in Bitcoin’s security.
Unstable network:
Fear of quantum vulnerabilities could cause market panic, affecting Bitcoin’s price and adoption.
Historically, even perceived technical risks, such as forks or protocol bugs, can lead to large swings in Bitcoin’s price.
Delayed Consensus:
If a quantum attack disrupts Bitcoin's PoW mechanism, it could lead to slower transaction verification or a network split.
Positive progress
While the risks are significant, the crypto industry’s proactive stance and advances in crypto defense offer a positive outlook:
The timeline is favorable for crypto: Experts generally agree that crypto-relevant quantum computers are at least 10-20 years away, which gives the crypto community plenty of time to transition to quantum-resistant standards.
Advances in cryptography: Post-quantum algorithms are not static but rapidly evolving. Researchers believe the pace of cryptographic innovation will outpace quantum advances.
Strengthening security posture: Integrating PQC into blockchain systems can make them more secure against quantum and classical threats, addressing the quantum threat to Bitcoin security and increasing trust in decentralized finance.
Market stability and opportunities
Transition Planning: Projects that transparently outline their quantum transition strategies are likely to attract greater investor confidence.
Innovation Catalyst: Quantum breakthroughs can drive blockchain innovations, such as quantum-secure wallets and decentralized systems optimized for post-quantum environments, addressing the impact of quantum chips on blockchain.
Finally, since crypto-relevant quantum computers are still years away, the crypto industry has time to adapt, ensuring a stronger and more secure decentralized future.
