Quantum Computers vs. Bitcoin
A seasoned Portfolio and Structured Product Manager with over 7 years of experience bridging traditional finance and Web3 venture capital. Currently managing 200+ portfolios, he specializes in connecting institutional banking expertise with emerging crypto markets.
Editor's Note: This article is authored by George Chu, and was originally published on his personal website. It is reprinted here with permission.
Quantum computing has long been a Sci-fi movie topic, where a supercomputer poses significant threats in the tech world by outraging cyber firewalls and taking over nuclear weapons within seconds. As these futuristic machines move closer to reality, one question comes up:
Will quantum computers break Bitcoin?
In this post, we’ll dive into why quantum computing poses a potential threat to Bitcoin’s security, how serious the danger truly is, and what precautions crypto developers can take to mitigate it.
Quantum computing has long been a Sci-fi movie topic, where a supercomputer poses significant threats in the tech world by outraging cyber firewalls and taking over nuclear weapons within seconds. As these futuristic machines move closer to reality, one question comes up:
Will quantum computers break Bitcoin?
In this post, we’ll dive into why quantum computing poses a potential threat to Bitcoin’s security, how serious the danger truly is, and what precautions crypto developers can take to mitigate it.
The Quantum Leap: Qubits Matter
Quantum computers leverage quantum bits (qubits) to perform calculations. They can simultaneously process an extensive amount of possibilities at once, whereas traditional laptops are only capable of dealing with a single calculation at a time.
This speedy computing innovation isn’t just a marginal upgrade. It unlocks the potential to solve complex mathematics problems that are practically impossible for classical computers, including breaking the security mechanisms that underpin overall cryptography.
There Are Two Aspects of the Bitcoin Network That Matter the Most
To understand the threat, we need to look at the two core cryptographic pillars of Bitcoin:
ECDSA (Elliptic Curve Digital Signature Algorithm)
The Bitcoin network relies on asymmetric cryptography or ECDSA: a private-public key pair is generated in such a manner that the two keys have a mathematical relationship. The “asymmetric” nature indicates the important concept that a public key can be easily derived from the private key, but it is mathematically impossible to reverse.
However, a famous algorithm published in 1994 by Peter Shor, known as Shor’s Algorithm, demonstrated that quantum computers can shatter this “invincible” cryptography.
Currently, it takes around 10 minutes for transactions to be settled on the Bitcoin network. As long as quantum computers can’t solve the cryptography within these time slots, the threat is manageable.
According to scientific estimation, modern quantum techniques take about 8 hours to break a private key, which is far from an instant threat to cryptocurrency. However, the field is still in its infancy and expected to grow exponentially. The FUD (Fear, Uncertainty, and Doubt) could come to reality in the coming years.
SHA-256 Algorithm
Bitcoin utilizes the Proof-of-Work (PoW) consensus, where “miners” compete in computational races to validate transaction batches. Whoever wins the competition is entitled to build the blocks and get awarded minted coins.
This race requires continually hashing data using SHA-256. Quantum computers dramatically reduce the time needed to clear the hash with another powerful technique called Grover's Algorithm. Grover is designed to speed up brute-force searches through unstructured data.
Miners who possess these cutting-edge quantum resources would gain asymmetric benefits to constantly win blocks (and BTC) over other competitors. While “miner monopoly” raises centralization concerns, the ability to breach private keys (via ECDSA) poses even more critical threats to the entire crypto industry.
Conclusion: Is the Threat Imminent?
Quantum computing threatens to turn encrypted assets into “naked” data and melt down ownership in the digital world. In this case, the security of the blockchain would be fundamentally broken.
Certain leaders, such as Vitalik Buterin (Ethereum founder), have dedicated efforts to steer Ethereum toward post-quantum cryptography solutions. The Bitcoin community, however, has not yet witnessed a clear direction on how to fundamentally mitigate the upcoming threat.
In short: Quantum attacks are not imminent today, but they represent critical threats that the entire crypto world will eventually face. The question isn't if, but when crypto developers will be well-prepared for its impact.