Arc Blockchain Publishes Post-Quantum Cryptography Roadmap

According to the official blog, Circle’s institutional blockchain, Arc, has unveiled a phased roadmap for post-quantum cryptography (PQ), planning to introduce post-quantum signature schemes at mainnet launch and progressively extend protection across the full stack—including private state protection, infrastructure hardening, and validator authentication. Arc’s mainnet will support post-quantum signatures from launch, using an opt-in mechanism that requires no forced migration or network-wide reset; users can autonomously create wallets with long-term security. The near-term goal is to extend quantum resistance to the private virtual machine (VM) layer, safeguarding private balances, private transactions, and private recipients, with public keys additionally wrapped in a symmetric encryption layer under privacy mode. The mid-term plan involves upgrading the infrastructure layer to align with industry standards such as TLS 1.3, covering access control, cloud environments, and hardware security modules (HSMs). The long-term objective is to strengthen validator signatures; given Arc’s block finality of less than one second, current assessments indicate relatively low quantum attack risk in this area, and upgrades will proceed steadily once post-quantum consensus tooling matures. Circle also warns that attackers may employ a “harvest now, decrypt later” strategy, urging institutions to begin planning their cryptographic migration paths as soon as possible.