Vitalik Buterin’s Stark Warning: Quantum Computers Could Shatter Crypto Security by 2040

Quantum computing's shadow looms over crypto's future—and Ethereum's creator just sounded the alarm.

The Encryption Countdown Begins

Buterin's projection puts blockchain's existential threat on a 15-year timer. Current cryptographic shields—the bedrock of Bitcoin, Ethereum, and every major blockchain—would crumble against quantum brute force. Transactions get exposed, wallets get drained, and trust evaporates overnight.

The Crypto Community's Quantum Dilemma

Developers already scramble for post-quantum solutions. Lattice-based cryptography and quantum-resistant algorithms enter lab testing while legacy systems sweat. Miners and validators face obsolescence unless they adapt—and adaptation doesn't come cheap. Meanwhile, Wall Street's quantum funds keep pouring billions into the very tech threatening to unseat them. Typical finance—betting on both the arsonist and the fire department.

Survival hinges on out-innovating the inevitable. Either crypto evolves or gets erased by 2040.

Ethereum co-founder Vitalik Buterin has raised fresh concerns about the future of cryptography in the age of quantum computing. Vitalik warns that quantum computers could break today’s cryptography by around 2040, with roughly a 20% chance that this could happen before 2030.

Why Quantum Matters for Crypto

Cryptography isn’t just about passwords or private emails, it secures the entire digital economy. From online banking to cryptocurrency wallets and smart contracts, all rely on algorithms designed to resist attacks from classical computers. 

A powerful quantum machine could, however, crack these defenses far faster, putting everything from financial assets to personal data at risk.

Ian Miers Raises the Concern of Soundness

Ian Miers explained that the real issue isn’t just the possibility of a future attacker decrypting old data. Instead, the deeper concern is soundness, ensuring that cryptographic systems, including blockchains, remain trustworthy even against the power of quantum computing.

Lack of market certainly WOULD prevent it if nothing else.

I'm not sure quantum changes that short term, or needs to: You have non-stark PQ schemes (e.g., ligero). And Groth16 etc are statistically zero-knowledge, so they should be post quantum private(not sound) IIRC.

He pointed out that STARKs, a cryptographic proof system, may be pushed to evolve into more zero-knowledge (zk) structures. This shift could come as they compete with post-quantum sound and ZK schemes, but he left an open question: Will those incentives be enough to ensure long-term safety?

Vitalik Buterin Brings Forecasts Into the Conversation

Responding to Miers, Vitalik Buterin highlighted predictions from forecasting platform Metaculus. According to its data, the median estimate for when quantum computers could break today’s cryptography is 2040, though there is about a 20% chance this happens before 2030.

This reminder underscores that while the threat may not feel immediate, it’s close enough on the horizon to demand serious attention today.

Metaculus's median date for when quantum computers will break modern cryptography is 2040:https://t.co/Li8ni8A9Ox

Seemingly about a 20% chance it will be before end of 2030.

Building a Post-Quantum Future

Despite the risks, the crypto community is not standing still. Researchers are already working on post-quantum cryptography, new algorithms designed to survive quantum attacks. 

At the same time, zk-proofs and STARKs continue to evolve, showing promise for more resilient systems.