Google Warns: Quantum Computers Could Crack Bitcoin Faster Than Expected

Google Research states that quantum computers may pose a threat to cryptocurrencies like Bitcoin (BTC) sooner than previously thought. According to new estimates, the computing power required to break blockchain security has decreased significantly. Meanwhile, Google is working toward a transition to quantum-resistant cryptography by 2029.

Less Computing Power Required for Attacks

In a recent blog post, Google explains that many blockchains rely on the so-called elliptic curve discrete logarithm problem (ECDLP-256) to secure wallets and transactions. However, new insights show that quantum computers can break this security more efficiently than previously assumed.

According to Google Research, the required capacity has become approximately twenty times lower. As a result, future quantum computers could perform these types of calculations within minutes.

This acceleration makes a new type of attack more realistic: the so-called “on-spend attack.” In this scenario, transactions are attacked while they are still waiting to be processed—after they have been sent but before they are permanently recorded on the blockchain. Since this process takes an average of ten minutes for Bitcoin, a brief window of opportunity for such an attack is created.

Transition to Post-Quantum Cryptography

Google emphasizes that there is still time to counter this threat, but the margin is shrinking. The company is calling on the crypto sector to accelerate the transition to Post-Quantum Cryptography (PQC), a form of security designed to withstand quantum attacks.

Earlier this month, Google announced its goal to be fully transitioned to PQC by 2029. The company suggests this timeline should serve as a guideline for the broader industry.

Beyond Crypto: The impact of quantum computing extends further than just cryptocurrency. Sectors such as national security and digital communication also depend on current cryptographic standards. Since 2016, Google has been collaborating with parties like Coinbase and the Ethereum Foundation to prepare for this transition.

The potential risks are already influencing investment decisions. For instance, some asset managers removed Bitcoin allocations from their model portfolios earlier this year, partly due to concerns regarding quantum computing.