Bitcoin’s Taproot could make quantum attacks easier than expected, new Google research says

Breaking Bitcoin’s blockchain with quantum computers may not be as difficult as once thought, and Bitcoin’s Taproot technology, which enables more efficient, private transactions, may be partly to blame, Google’s Quantum AI team said Monday in a blog post and newly published whitepaper.

The team said the computing power required to break Bitcoin’s security may be far lower than previously assumed, raising fresh questions about how soon quantum threats could become a reality.

In a new whitepaper, researchers found that cracking the cryptography used by Bitcoin and Ethereum could require fewer than 500,000 physical quantum bits, or qubits, well below the “millions” often cited in recent years.

Google has previously pointed to 2029 as a potential milestone for useful quantum systems, saying migration needs to come before that, making the paper’s finding that attacks may require less computing power more significant.

Quantum computers use qubits instead of traditional bits and…