Quantum computers are coming for crypto. The industry is racing to prepare
Blockchain networks built on decades-old cryptography face a potential existential threat as developers begin planning a costly and complex security overhaul.
The cryptocurrency industry is beginning to prepare for a new and potentially existential challenge: the possibility that quantum computers could eventually break the cryptographic systems that protect digital assets, transactions and wallets.
Quantum computers are designed to solve certain complex mathematical problems far faster than today’s most advanced conventional computers. If the technology reaches the required level of capability, it could undermine traditional encryption methods that secure digital information, posing a major risk to the roughly $2 trillion global cryptocurrency market, which relies on blockchain networks protected by decades-old cryptography.
While practical quantum computers capable of breaking current encryption remain experimental, concerns have intensified following recent advances in the field. Research from Google, one of several technology companies developing quantum systems, suggested that the timeline for such attacks could be shorter than previously believed. Google has said that quantum computers capable of breaking encryption could arrive by 2029, whereas previously many experts expected such capabilities to remain at least a decade away.
Research from Citigroup and other institutions has also suggested that advances in quantum computing, alongside breakthroughs in artificial intelligence, are accelerating the timeline in which cryptocurrencies could become vulnerable to attacks.
Recognizing the broader national security implications of quantum technology, U.S. President Donald Trump recently issued executive orders aimed at strengthening American quantum capabilities.
Some cryptocurrency companies and blockchain developers are already preparing plans to upgrade their networks with quantum-resistant cryptography, a potentially years-long process that could require significant changes to the infrastructure underlying digital assets.
“It’s the most direct and existential threat towards cryptocurrencies and crypto networks,” said Chris Tam, head of quantum innovation at BTQ Technologies, a company focused on quantum security.
Blockchains rely on decades-old cryptography
Most blockchain networks rely on elliptic-curve cryptography, a system developed decades ago, to generate the public and private keys and digital signatures used to verify ownership of crypto assets and authorize transactions.
Public keys are mathematically derived from private keys. While current computers cannot realistically calculate a private key from a public key, a sufficiently powerful quantum computer could theoretically perform that calculation, allowing attackers to forge digital signatures and authorize fraudulent transactions.
The threat is particularly significant for public blockchains because transactions are transparent and irreversible, unlike many traditional payment systems.
“Crypto especially is uniquely exposed because blockchains are transparent and permanent,” said Utkarsh Ahuja, managing partner at crypto investor Moon Pursuit Capital.
Bitcoin, the world’s largest cryptocurrency, is viewed as especially vulnerable because its 17-year history has created a large number of publicly visible keys.
Around 35% of bitcoin’s circulating supply could potentially be exposed to a quantum computing attack, according to an unpublished June 2026 working paper by independent researcher Ahmed Raza Muhammad Umer. Other research published last year estimated that the figure could be as high as 50%.
A successful attack involving the theft and sale of a significant amount of cryptocurrency could trigger a sharp market reaction, said Cristiano Ventricelli, vice president and senior analyst of digital assets at Moody’s Ratings.
“Everyone will feel the impact,” he said.
The concern has already influenced some investors. Christopher Wood, global head of equity strategy at Jefferies, removed a 10% bitcoin allocation from his model portfolio in January, citing the long-term “existential” threat posed by quantum computing.
The race to build quantum-resistant blockchains
Despite the risks, many crypto executives and researchers believe the industry still has time to adapt. They argue that blockchains can eventually migrate to new forms of “post-quantum” cryptography designed to withstand attacks from quantum computers.
However, moving too quickly also carries risks. Post-quantum cryptographic systems are still evolving, and many alternatives require significantly larger digital signatures than current systems. That could increase storage and bandwidth requirements, raise costs and affect user experience, particularly on blockchains with technical limitations such as bitcoin’s fixed block-size structure.
“There is an engineering challenge ahead, but there are engineering solutions already on the table,” said Zach Pandl, head of research at crypto asset manager Grayscale.
The transition could take years. One senior cybersecurity executive at a major crypto company estimated that his organization would need about two years to become fully quantum-resistant. Others compared the potential overhaul to the Y2K computer transition, when companies spent more than $300 billion globally preparing for the millennium bug.
The challenge is particularly complicated because most blockchains are decentralized. Unlike traditional technology systems, they rely on communities of developers, users and stakeholders that must agree on major changes.
None of the top 20 blockchains have yet implemented a post-quantum signature algorithm, according to people interviewed for this story. In bitcoin’s case, developers and market participants remain divided over which solution to adopt and when to begin the transition.
The Ethereum Foundation, which supports the blockchain behind ether, the second-largest cryptocurrency, has said it is targeting 2029 for full protection against quantum threats.
“The sort of disaster scenario is that it happens way sooner than we think,” said Christopher Smith, CEO of Quantus, a blockchain that already uses post-quantum cryptography.
Some networks are moving earlier. The Algorand Foundation, which supports the Algorand blockchain, recently published a post-quantum roadmap and plans to begin supporting post-quantum accounts later this year, according to Bruno Martins, the foundation’s chief technology officer.
“It felt right to start doing something now, because it’s responsible to have a plan,” Martins said.
