Circle Unveils Quantum Security Roadmap for Arc Blockchain

Circle, the issuer of the USDC stablecoin, has outlined a plan to make its Arc blockchain quantum-resistant. The rollout will begin at the mainnet launch in 2026 with opt-in quantum-proof wallets and signatures.

Circle emphasized that quantum resilience cannot be just theoretical or pilot-based but must be integrated into infrastructure. This comes after Google warned that functional quantum computing could arrive sooner than expected, potentially breaking Bitcoin's cryptographic protections within nine minutes.

The company flagged that wallets with previously exposed public keys face particular risk and urged migration before a predicted date, known as Q-Day. After the mainnet launch, Circle plans to introduce a privacy layer for Arc, shielding balances, transactions, and financial data from view.