A leading expert in quantum computing has sounded the alarm on the potential threats of quantum attacks to Bitcoin.
John Martinis, a Nobel Prize-winning physicist who helped build Google's quantum computers, believes that breaking encryption is one of the easier applications for quantum computing. He warns that Bitcoin could be among the earliest real-world targets of this technology, due to its reliance on elliptic curve cryptography.
The concern centers on a specific vulnerability window when a bitcoin transaction is broadcast and its public key becomes visible before it is confirmed onchain. A powerful quantum computer could use this window to derive the corresponding private key and redirect funds before final settlement.
However, Martinis notes that building a quantum computer capable of executing such an attack remains one of the hardest engineering challenges in modern science. He estimates that it may take five to ten years to develop such a machine and cautions against assuming the threat is imminent.