Fidelity Flags Quantum Threat to Bitcoin's Underlying Security
Fidelity Digital Assets, the crypto arm of financial services giant Fidelity Investments, has published a research report examining whether Bitcoin's underlying security could be broken by quantum computers.
The report, authored by senior research analyst Daniel Gray, is clear that cryptographically relevant quantum computers (CRQCs) do not yet exist. However, Fidelity argues the threat warrants preparation now rather than a scramble later.
Bitcoin currently uses two signature schemes, ECDSA and Schnorr, both of which rely on a mathematical assumption called the elliptic curve discrete logarithm problem. A sufficiently powerful quantum computer could reverse this math puzzle, exposing a user's private key when a transaction is signed.
A recently formalized Bitcoin Improvement Proposal (BIP) called SHRINCS aims to address this issue by combining two types of quantum-resistant signature schemes. This proposal balances security against the practical constraint that quantum-safe signatures are significantly larger than current ones, potentially slowing network throughput.