Circle, the stablecoin issuer behind USDC, has published a post-quantum security roadmap for its layer-1 blockchain, Arc, outlining plans to introduce quantum-resistant protections across every layer of the network’s technology stack. The company announced the initiative on Thursday, describing a phased approach that begins with quantum-proof wallets and signatures at the time of Arc’s mainnet launch. Circle emphasized that waiting for the threat to materialize is not a viable strategy, stating that quantum resilience must appear in live infrastructure rather than research papers or distant planning documents.
The first phase of the rollout will make post-quantum signature schemes available on Arc when the network goes live on mainnet, currently expected sometime in 2026. This feature will be opt-in at launch, giving users the choice to adopt quantum-resistant wallets from the outset. Protections at the validator level and across surrounding infrastructure are planned for later stages of the rollout.
Circle’s announcement follows recent warnings from Google and researchers at the California Institute of Technology, who cautioned that functional quantum computers could arrive sooner than previously anticipated and may require less computing power than earlier estimates suggested. Google indicated that quantum computers could potentially break Bitcoin‘s cryptographic protections in as little as nine minutes. Circle cited these developments as a reason the industry cannot afford to delay action, particularly for active wallet addresses whose public keys have already been exposed through signed transactions.
Following the mainnet launch, Circle plans to introduce an additional quantum solution designed to keep balances, transaction data, and other financial information private. Over the longer term, the company intends to extend quantum protections to Arc validators and its offchain infrastructure, which includes access controls, cloud environments, and hardware security systems. Arc is currently live on a public testnet and is designed to give enterprises broad access to use cases built around the USDC stablecoin.
The broader cryptocurrency industry largely acknowledges that quantum computing represents a genuine threat, though debate continues over the precise scope of the risk. Some argue that only wallets with exposed public keys face immediate vulnerability, while others contend that all digital assets could eventually be at risk. A Google research paper published on March 31 identified Algorand as potentially the most quantum-ready blockchain, while the Ethereum and Solana ecosystems are each actively developing solutions ahead of what researchers refer to as Q-Day.
The Bitcoin ecosystem remains more divided on how developers should respond. Blockstream CEO Adam Back, one of the most prominent voices in the Bitcoin community, has argued that quantum risks are widely overstated and that no action is necessary for several decades. Taking a contrasting position, security researcher Ethan Heilman and others have proposed a new output type for Bitcoin known as Pay-to-Merkle-Root, formalized through Bitcoin Improvement Proposal 360, which aims to shield Bitcoin addresses from potential short-exposure quantum attacks. Heilman told reporters in February that implementing this proposal could take as long as seven years.
Originally reported by CoinTelegraph.
