Circle's Arc public chain releases quantum cryptography roadmap, covering full-stack upgrades from wallets to validators

Golden Finance reports that on April 6, according to the official blog, Circle’s institutional blockchain arm Arc released a phased upgrade roadmap for post-quantum cryptography (PQ). The plan is to introduce post-quantum signature schemes when the mainnet goes live, and gradually cover end-to-end layers such as private state protection, infrastructure hardening, and validator attestation/verification. At launch, the Arc mainnet will support post-quantum signatures using an optional opt-in mechanism, with no forced migration or whole-network reset. Users can create wallets on their own that have long-term security. The near-term goal is to extend quantum resistance to the private virtual machine (VM) layer, protecting private balances, private transactions, and private recipients. In privacy mode, the public key will be additionally encapsulated with a symmetric encryption layer. The mid-term plan is to advance upgrades to the infrastructure layer to align with industry standards such as TLS 1.3, covering access control, cloud environments, and hardware security modules (HSM), among others. The long-term goal is to complete validator signature hardening. Given that Arc’s block-production finality time is less than 1 second, the current assessment suggests that quantum attack risk in this step is relatively limited. The effort will be rolled out steadily once the post-quantum consensus tooling pipeline matures. Circle also cautioned that attackers may adopt a “collect now, decrypt later” strategy. Institutions should plan their cryptographic migration paths as early as possible.