Bitcoin and Crypto Face the Quantum Threat: Security or Speed?

Quantum Speed Threatens Crypto’s Core

The cryptographic foundations of Bitcoin and other major cryptocurrencies are under increasing scrutiny as quantum computing advances accelerate. In March 2026, multiple research papers suggested that quantum computers could break widely used cryptographic systems sooner than previously anticipated. The core concern centers on algorithms like Shor’s, which allow quantum machines to solve problems—such as factoring large numbers and cracking digital signatures—that keep crypto assets secure.

A recent study from Google’s Quantum AI team found that a sufficiently powerful quantum computer, with fewer than 500,000 physical qubits, could derive a Bitcoin private key from its public key in about nine minutes. This is a drastic reduction compared to the years or even centuries required by conventional computers. The announcement has forced blockchain developers and security experts to reconsider how quickly their networks could be compromised if a so-called "Q-Day" arrives—the moment when quantum computers can break existing cryptography at scale.

Google's paper estimates that today's largest quantum processors, at around 1,000 qubits, are still far from the 500,000-qubit threshold needed for such attacks.

Nine-Minute Bitcoin Heists Loom Closer

Bitcoin transactions rely on the elliptic curve discrete logarithm problem for security. When someone sends bitcoin, their public key is revealed and broadcast to the network, where it sits in the mempool until a miner includes it in a block—a process that averages around 10 minutes. Google’s research indicates that an attacker with access to a quantum computer could pre-compute much of the work needed to break this link, requiring only about nine minutes to derive the private key once the public key appears.

This gives attackers a 41% chance of stealing funds before the transaction is confirmed.

On paper, Bitcoin’s transparent design is meant for openness and auditability—but quantum computing turns that openness into a liability. It’s uncertain how quickly users and developers could adapt if Q-Day arrived suddenly, especially since upgrading Bitcoin to post-quantum security standards would take years.

Security Slows Down Solana’s Network

Solana, known for its speed, faces a harsh tradeoff when experimenting with quantum-resistant cryptography. Project Eleven, working with Solana Foundation, deployed a test environment using quantum-safe signatures that are between 20 and 40 times larger than current ones. The result was stark: network performance dropped by about 90%, raising questions about whether users would accept such slowdowns for better security.

Fast blockchains may not stay fast if they want to survive Q-Day.

Bitcoin’s Unspent Keys: Sitting Ducks

Roughly one-third of all bitcoin—about 6.9 million BTC—are held in wallets where the public key has already been exposed. These funds are particularly vulnerable because their keys can be targeted by quantum attacks without waiting for new transactions to reveal them. “Q-Day” could potentially expose over $711 billion in value sitting in older addresses, according to decrypt.co.

Ethereum faces similar risks: one report identified vulnerabilities threatening $100 billion in assets due to traditional cryptographic methods still in use.

Why it matters: Practical Impact Beyond Theory

The threat isn’t just theoretical—some projects are already moving toward solutions. Naoris Protocol launched its mainnet with post-quantum cryptography this week, validating over 100 million transactions using algorithms approved by the U.S. National Institute of Standards and Technology. During its testnet phase, Naoris Protocol processed more than 106 million post-quantum transactions and detected over 603 million threats globally.

However, practical adoption comes with costs: larger signature sizes slow down networks dramatically, as seen with Solana’s 90% performance drop during testing. Even so, Naoris Protocol has created more than 3.3 million wallets and activated over one million security nodes worldwide; its NAORIS token currently holds a $36 million market cap.

Despite these advances, upgrading established blockchains like Bitcoin will require years of coordinated effort—and many users remain unaware that their holdings may be at risk sooner than expected if quantum computing breakthroughs continue apace.

Short-term watchlist

Naoris Protocol’s quantum-resistant blockchain mainnet went live on Thursday, and if its post-quantum cryptography successfully blocks transactions using traditional methods as claimed, it would immediately demonstrate a working mitigation against vulnerabilities highlighted in recent Google research estimating that fewer than 500,000 qubits could break Bitcoin’s cryptography—a threshold not yet reached by current quantum processors.