Overview
- Circle, which published the roadmap Monday, said Arc will let users opt in to quantum-resistant wallet signatures at mainnet, with the launch date still unannounced.
- The plan rolls out in stages that start with wallets, add quantum-protected private smart‑contract state next, and later harden infrastructure and validator authentication including TLS upgrades and key management.
- Arc remains EVM-compatible and uses USDC for gas, allowing developers to keep existing tooling while institutions gain stronger security without disruptive resets.
- Circle pointed to new warnings from Google and Caltech and to NIST’s “harvest now, decrypt later” risk, noting that addresses with exposed public keys may need to move before a potential Q‑Day projected early next decade.
- Post‑quantum signatures are larger and can tax bandwidth, but Arc’s sub‑second finality leaves attackers roughly a 500‑millisecond window for short attacks, which narrows practical exposure today.