Will Quantum Computing Kill Bitcoin?

Forbes

2 days ago

Quantum computers could theoretically break Bitcoin's encryption and destroy the cryptocurrency ... More overnight, threatening the investments of 500 million global holders and trillions in market value.
Bitcoin and other cryptocurrencies are now embedded in the global financial system. Countries are creating strategic reserves, and institutional investors, from hedge funds to pension schemes, are allocating capital to digital assets.
Many individuals, businesses, and even governments are exposed to price fluctuations in this notoriously volatile market. But could it all collapse overnight if quantum computing renders the technology behind cryptocurrencies obsolete, potentially causing trillions of dollars in value to vanish?
That's the risk some experts associate with quantum computing. These futuristic machines harness the strange properties of quantum mechanics to perform specific types of calculations exponentially faster than even the most powerful supercomputers. Given enough power, quantum computers could one day break the cryptographic foundations of blockchain systems like Bitcoin.
So, how real is this threat? Could it mean the end of crypto or the start of a new chapter in the age of post-quantum security?
At the start of 2024, an estimated 500 million people globally held Bitcoin or other cryptocurrencies, a 34% increase from the year before. The majority of holders reside in Asia and North America. In many cases, these assets represent a substantial portion of personal wealth or national reserves.
If a technological advance were to render these assets insecure, the consequences could be severe.
Cryptocurrencies function by ensuring that only authorized parties can modify the blockchain ledger. In Bitcoin's case, this means that only someone with the correct private key can spend a given amount of Bitcoin.
Bitcoin currently uses cryptographic schemes such as the Elliptic Curve Digital Signature Algorithm (ECDSA) and Schnorr signatures to verify ownership and authorize transactions. These systems rely on the difficulty of deriving a private key from a public key, a task that is computationally infeasible for classical computers.
This infeasibility is what makes "brute-force" attacks, trying every possible key, impractical. Classical computers must test each possibility one by one, which could take millions of years.
Quantum computers, however, operate on different principles. Thanks to phenomena like superposition and entanglement, they can perform many calculations in parallel. In 1994, mathematician Peter Shor developed a quantum algorithm capable of factoring large numbers exponentially faster than classical methods. This algorithm, if run on a sufficiently powerful quantum computer, could undermine encryption systems like ECDSA.
The core difference lies in how quantum and classical computers handle data. Classical computers process data as binary digits (bits), either 0s or 1s. Quantum computers use qubits, which can exist in multiple states simultaneously.
As of 2024, the most advanced quantum computers can process around 1,000 qubits, but estimates suggest that breaking Bitcoin's ECDSA encryption would require a machine with 10 million to 300 million fault-tolerant qubits, a goal that remains years or even decades away.
Nonetheless, technology often advances unpredictably, especially now that AI tools are accelerating research and development across fields, including quantum computing.
This is why work on quantum-safe (or post-quantum) cryptography is already well underway. The U.S. National Institute of Standards and Technology (NIST) is leading efforts to standardize cryptographic algorithms that are secure against quantum attacks, not just to protect cryptocurrencies but to safeguard the entire digital ecosystem, from banking systems to classified government data.
Once quantum-safe standards are finalized, Bitcoin and other blockchains could adapt accordingly. Bitcoin's open-source software is managed by a global community of developers with clear governance protocols for implementing updates. In other words, Bitcoin is not static; it can evolve to meet new threats.
Could quantum computing kill Bitcoin? In theory, yes, if Bitcoin failed to adapt and quantum computers suddenly became powerful enough to break its encryption, its value would plummet.
But this scenario assumes crypto stands still while quantum computing advances, which is highly unlikely. The cryptographic community is already preparing, and the financial incentives to preserve the integrity of Bitcoin are enormous.
Moreover, if quantum computers become capable of breaking current encryption methods, the consequences would extend far beyond Bitcoin. Secure communications, financial transactions, digital identities, and national security all depend on encryption. In such a world, the collapse of Bitcoin would be just one of many crises.
The quantum threat is real, but so is the work being done to prevent it.
So, if you're among the millions with a bit of Bitcoin tucked away in the hope it will one day make you rich, well, I can't guarantee that will happen. But I don't think you need to worry that quantum computing is going to make it worthless any time soon.