Daily Update

Is Google Correct That Bitcoin Could Be Cracked in 9 Minutes With Quantum Computing?

4 min read

Google just published a paper showing that future quantum computers could break Bitcoin’s encryption with 20 times fewer resources than previously thought. The headlines are scary. The reality is more nuanced — and more interesting.

Three key facts to take away:

  1. Google’s quantum team found that cracking Bitcoin’s encryption would require fewer than 500,000 physical qubits — down from earlier estimates in the millions. That’s a 20x reduction in the resources needed for a real attack.
  2. No quantum computer today can execute this attack. Google’s most advanced chip, Willow, has 105 qubits. The attack requires 500,000. We’re not there yet — but the gap is closing faster than expected.
  3. This is not a Bitcoin-only risk. The same cryptography protects banks, military systems, intelligence agencies, and the entire global financial system. If quantum breaks Bitcoin, traditional finance has a much bigger problem — and a slower path to fixing it.

On Monday, Google’s Quantum AI division dropped a paper that sent shockwaves through the crypto world. The headline version: quantum computers could crack Bitcoin’s cryptography in about nine minutes, hijacking transactions before they confirm.

The more accurate version: Google showed that the theoretical resources needed for such an attack are significantly lower than anyone previously estimated. Not that the attack is possible today. But that the timeline to prepare just got shorter.

What Google Actually Found

Bitcoin’s security relies on elliptic curve cryptography (ECDLP-256) — the same math that protects most of the internet. Breaking it requires solving a problem that’s essentially impossible for classical computers.

Quantum computers change that equation. Using Shor’s algorithm, a sufficiently powerful quantum machine could crack ECDLP-256. The question has always been: how powerful?

Previous estimates said you’d need millions of physical qubits. Google’s new research says fewer than 500,000 — and possibly as few as 1,200 high-quality logical qubits with 70-90 million operations. That’s a 20x reduction in the estimated resources.

For context: Google’s current best quantum chip, Willow, has 105 qubits. So we’re still orders of magnitude away. But quantum computing is advancing rapidly, and the gap between “theoretical threat” and “practical threat” just narrowed considerably.

Why 6.9 Million Bitcoin Are Already Exposed

Here’s the part most people miss. The quantum threat doesn’t affect all Bitcoin equally.

Bitcoin is only vulnerable when the public key is visible on the blockchain. For most wallets, the public key is only revealed when you spend — creating a brief window of exposure. But roughly 6.9 million BTC (about $467 billion / R7.9 trillion) sit in addresses where the public key is already exposed, either from older transaction types or from Bitcoin’s Taproot upgrade, which makes keys visible by default.

Google specifically flagged Taproot as widening the attack surface. That’s worth knowing if you’re a Bitcoin holder.

The 9-Minute Window

The scariest number in Google’s paper: nine minutes. That’s how long a quantum attack on an in-flight transaction would take — fast enough to potentially beat Bitcoin’s confirmation time roughly 41% of the time.

In practice, this means a sufficiently advanced quantum computer could intercept a Bitcoin transaction after it’s broadcast but before it’s confirmed, derive the private key from the public key, and redirect the funds. All in under ten minutes.

Again — no computer can do this today. But this isn’t science fiction either. Google’s timeline suggests the crypto industry needs to “change the locks” well before quantum computers reach this capability, not after.

This Is Not a Bitcoin Problem — It’s an Everything Problem

Here’s what the headlines won’t tell you: Bitcoin is the least of anyone’s worries if quantum computing reaches this level.

The same elliptic curve cryptography that protects Bitcoin also protects the global banking system, military communications, nuclear launch protocols, intelligence agencies, government databases, and virtually every secure system on the internet. RSA and ECC — the two encryption standards that underpin online banking, SWIFT transfers, classified military networks, and diplomatic communications — are all vulnerable to the same quantum attack.

If a quantum computer can crack Bitcoin in nine minutes, it can also crack your bank account, your medical records, and your government’s most closely guarded secrets. The entire global financial system — trillions of dollars in daily transactions — runs on the same mathematical assumptions that Google’s paper just challenged.

In other words, if quantum computing breaks Bitcoin, we have much bigger problems than cryptocurrency. The traditional financial system, which processes over $7.5 trillion (R126.7 trillion) in daily foreign exchange transactions alone, faces the same fundamental vulnerability. Banks, stock exchanges, central banks — all of them rely on cryptography that a sufficiently powerful quantum computer would render useless.

Bitcoin actually has an advantage here: it’s open-source, transparent, and its community is already working on post-quantum solutions. Traditional banks and government agencies operate behind closed doors, and their upgrade timelines are far less visible.

Bitcoin’s Response

The good news: this isn’t a surprise. The crypto community has known about the quantum threat for years. What Google’s paper changed is the urgency.

Ethereum developers have already launched a post-quantum migration effort. Bitcoin Core developers are working on quantum-resistant signature schemes. And Google itself — notably — published this as responsible disclosure, working with the crypto community rather than against it.

The recommended path forward is transitioning to post-quantum cryptography (PQC) — new mathematical foundations that quantum computers can’t crack. NIST finalised its first PQC standards in 2024, and the building blocks exist. The challenge is implementing them across a decentralised network with no CEO to mandate an upgrade.

Bitcoin has done hard upgrades before. SegWit, Taproot, and countless soft forks prove the network can evolve. But this one has a deadline — and Google just moved it closer.

What South African Holders Should Know

If you hold Bitcoin, this doesn’t mean your funds are at risk today. It means the network needs to upgrade its cryptography before quantum computers become powerful enough, and the timeline for that upgrade just became more urgent.

The fact that Google — one of the most advanced quantum computing operations on earth — chose to publish this research openly rather than exploit it says something important. Bitcoin is being treated as critical infrastructure worth protecting, not a toy to break.

For now, the practical steps are simple: use modern wallet types, avoid address reuse, and watch for the Bitcoin community’s post-quantum roadmap as it develops.

The threat is real. The timeline is measured in years, not months. And the response is already underway.

Sources:

Exchange rate used: $1 = R16.89 (1 April 2026)

Leon Kowalski