Quantum Won’t Kill Crypto, But It Could Accelerate Wall Street’s Adoption of Blockchain

For many in the crypto industry, the specter of quantum computing has become the stuff of existential dread. According to popular doomer narratives, public blockchains like Bitcoin will be among the first target of quantum-based attacks that will wipe out trillions of dollars.

In this view, public blockchains most salient feature, decentralization, is an Achilles heel that will impede the implementation of defensive upgrades to protect from quantum-powered hackers. The doomers argue that networks like Bitcoin, Ethereum and Solana will be helpless against a threat that will one day smash the public-key cryptography that has long made them secure.

This makes for a dramatic story, but the premise is misguided. While the threat is real, the conclusion–that quantum will kill crypto–is simply wrong.

First, it’s important to recall that it is not only blockchains that are at risk from a quantum-powered attack. Much of the internet as we know it is vulnerable to Q-day, or the moment when quantum machines finally muster the capacity to pick the locks of the world’s existing encryption defenses.

Exposed are hundreds of trillions of dollars of the world’s assets, as well as our most sensitive private data. Already, bad actors have initiated “harvest now, decrypt later” schemes to strike hard and fast when Q-day finally arrives. Alarmed, governments have responded by mandating action plans to prepare. Yet, amid this scramble to shore up our digital bulwarks, the one industry that seems to have experienced a particular sense of foreboding over quantum advancements also happens to be the most capable of meeting the challenge.

I’m referring, of course, to the crypto industry. Because of a long-held open-source ethos, public blockchains and associated infrastructure have long faced attack by malicious actors. Builders of these networks have learned to become survivors, constantly patching up vulnerabilities and both anticipating and responding to myriad other threats. Compared to other industries, the crypto industry’s response to new cyberthreats has been lightning fast and, indeed, many have already sprung to action in building defenses ahead of Q-day’s arrival.

Conversely, it is legacy financial systems that appear prone to rolling out insufficient responses to meet pressing challenges. Back in 2018¹, for example, the SWIFT network began a major initiative to modernize its 1970s-era global banking-transfer messaging technology. And the time it took to complete this undertaking? Seven years.

Granted, SWIFT is a sprawling network of 11,000 institutions that had to coordinate efforts across 200 countries. But the upgrade it undertook—modernizing a messaging format—was simple in comparison to the broader task at hand: swapping out the guts of decades-established cryptography layers that touch certificates, hardware, software, vendors and counterparties across the financial system.

It’s not just SWIFT. There’s a long history of significantly delayed overhauls to a wide variety of key pieces of core financial infrastructure, all of which bode ill for timely upgrades to meet the quantum challenge. A planned revamp of the Federal Reserve’s high-value wire system began in 2015², but only managed to cross the finish line in July 2025.³ In 2016, the Bank of England⁴ began planning an overhaul to its central ledger for handling interbank settlements. While a target completion date was set for 2021, it didn’t actually happen until 2025⁵ (and aspects of this upgrade are still ongoing).  

Even as organizations like SWIFT have announced ambitious efforts to tackle the quantum threat, history suggests that we temper our expectations that the sprawling surface area of legacy financial services, governments and other industries will be ready when Q-day arrives. According to the U.S. Government⁶ some of the most critical digital infrastructure must be quantum secure by 2030—that four year timeline is half of what it took SWIFT to undergo a far less ambitious upgrade.  

That’s why it’s heartening to see workable solutions emerging from the cryptoverse’s many world-class cryptographers, many of whom already have gone on the quantum offensive. Indeed, leading blockchain organizations have published comprehensive plans (JJR1)⁷ for achieving post-quantum readiness well before 2030. Even Ethereum, known for prioritizing decentralization over speed, has moved without hesitation, laying out 2029 in the network’s roadmap⁸ as when it will be quantum ready. 

At the same time, the crypto industry has spawned a wave of new startups that are building a wide variety of novel post-quantum picks and shovels, ranging from wallets to payment infrastructure. Resources and talent indeed are being marshalled in a profound way, and it increasingly looks as though the crypto industry might have just leapfrogged the traditional players in the broader pursuit of achieving quantum readiness.

This is encouraging and so too are the growing legions of finance professionals who see great promise in blockchain networks and tokenization. As they confront the enormous task of upgrading their outdated legacy financial infrastructure, many of these professionals instead will find it easier to simply switch over to using quantum-hardened blockchains.