Quantum Risks: Chaincode Labs Assessed the Threat to Bitcoin.
Experts from the research organization Chaincode Labs published a detailed report on the potential threats of quantum computers to Bitcoin. The 55-page document was prepared by Dr. Anthony Milton and Clara Schickelman in May 2025.
How Many Bitcoins Are at Risk
According to the authors' estimates, between 20% and 50% of all bitcoins in circulation (4-10 million BTC) are potentially vulnerable to attacks using cryptographically relevant quantum computers (Cryptographically relevant quantum computer, CRQC).
The most accurate estimate from Project Eleven as of January 17, 2025, indicates 6,262,905 BTC. The funds are distributed as follows:
Satoshi-era bitcoins – between 600,000 and 1.1 million BTC remain on P2PK type addresses with fully exposed public keys;
Lost coins – between 2 and 3 million BTC belong to users who have lost access to their private keys. Not all of them are quantum vulnerable, but a significant portion is at risk;
Addresses with exposed keys – millions of bitcoins are on addresses where public keys have been revealed due to their reuse.
