Quantum Risk Looms for Crypto Wallet Signatures
The threat of quantum computers to major blockchains is real and growing more imminent. Researchers warn that a breach could occur within eight to 18 years, but say it's not a concern for mining hashes. Instead, quantum attackers would target digital signatures used in wallet ownership.
NIST has already finalized its post-quantum cryptography standards and advises organizations to start migrating to quantum-resistant systems. Experts estimate that the earliest realistic breach could happen as early as 2034, with a 19% to 34% chance of a cryptographically relevant quantum computer being developed by then.
The main risk lies in elliptic curve digital signatures used by Bitcoin and Ethereum. Shor's algorithm could theoretically solve these mathematical problems, allowing attackers to forge transactions. However, Grover's algorithm would only offer a square-root speedup against hash functions, leaving 256-bit hashes with roughly 128-bit effective security.
Crypto networks are facing pressure to adopt post-quantum protections before cryptographically relevant hardware arrives. NIST expects to deprecate quantum-vulnerable algorithms by 2035 and Google has set an internal migration target near 2029, while Ethereum's roadmap also targets full post-quantum protection around the same time.