Approximately 6,786,955 Bitcoins (BTC), worth approximately US$626 billion, are currently theoretically vulnerable to quantum computing attacks because their public keys are tied to addresses that are already publicly available on the network.
That amount represents Approximately 33% of the total Bitcoin supply.
According to the Project 11 site, 13,778,861 addresses were identified with non-zero balances and public keys. This is a necessary requirement to allow attackers to attempt to reconstruct private keys in future scenarios with sufficiently powerful quantum computers.
Notable cases include addresses linked to cold wallets on large exchanges, such as reused P2SH (Payment to Script Hash) addresses. 248,597 BTC associated with Binanceand the other was 165,542 BTC, which was also released by reusing the script.
Vulnerability does not imply immediate risk. However, this data quantifies what portion of the supply will be in a delicate situation if quantum computing achieves the ability to break Bitcoin’s transaction signature scheme, called ECDSA.
Technical proposal and quantum risk assessment
David Duong, Head of Investment Research at Coinbase, said: “Promising” technology proposal to reduce risks.
In it, he mentioned BIP-360, reported by CriptoNoticias, which allows “public keys to be taken off-chain, paving the way for post-quantum signatures.”
It also includes BIP-347, which proposes enabling one-time signatures based on hashes.
Duong added that best practices at the operational level include “developing customer-facing procedures to avoid address reuse, move vulnerable UTXOs to a single destination, and institutionalize quantum-ready operations.”
“We do not believe that quantum computing is an immediate threat, as we are orders of magnitude further away from being able to break Bitcoin encryption with current machines. Still, there is no doubt that the open source community remains vigilant and is designing a post-quantum path.”
