The network's roadmap spans wallets, private smart contract state, validator authentication, and supporting infrastructure. Unlike approaches that would force disruptive network-wide resets, Arc's design is opt-in with no mandatory migration required, according to the company.
Post-quantum signature support will arrive alongside the forthcoming mainnet launch, while quantum-resistance private state protection is noted as a “near-term” enhancement. Post-quantum-designed infrastructure will come later, followed by the “long-term” improvement of validator signature hardening.
The technical challenges are significant. While classical signatures measure 64-65 bytes, post-quantum signatures can be an order of magnitude larger. Arc's sub-second block finalization leaves attackers only a 500 millisecond window to forge validator signatures. The roadmap document emphasizes that blockchains need quantum-resistant protections across every layer of the stack, not just at the wallet level.
The move highlights challenges facing established networks—Bitcoin's migration to post-quantum wallets alone could take months of continuous processing in a best-case scenario, Arc's documentation states.
"The organizations that lead this transition will be the ones that started building before the urgency became undeniable,” Arc’s post reads. The technical complexity of quantum-resistant migrations poses significant hurdles for networks with large user bases and extensive infrastructure.
Most major blockchain networks lack adequate preparation for quantum threats that could render current security obsolete, making proactive approaches increasingly critical for protecting long-lived digital assets.
