Move over, legacy crypto. Circle’s Layer-1 blockchain Arc, built for institutional and financial use of stablecoins, will debut with quantum-resistant features designed to survive a future where traditional blockchains could crumble under quantum attacks.
“On the mainnet, Arc will introduce a post-quantum signing scheme, giving users a practical design path to create quantum-resistant wallets,” Arc said in an update on Thursday. The update did not mention the timeline for the mainnet launch.
It means that Arc is building in quantum resistance from day one, unlike legacy chains, which may be waiting to add this feature later as a patch. So when users create a wallet on the mainnet, they can choose a signing method that future quantum computers cannot break. This will ensure the long-term security and protection of the cryptoassets in the wallets.
Each blockchain wallet relies on a digital signature or super-secure key to prove ownership of your tokens and authorize transactions. When you press “send” on your crypto, your wallet signs the transaction with this code and the network verifies it before moving the coins. Current computers are not powerful enough to exploit this process, access your key, and deplete your coins.
However, a future quantum computer could do so in at least two ways: a long attack and a short attack, as CoinDesk explained on Sunday.
In short, what seems unbreakable today may not be unbreakable tomorrow, which is what Arc offers a quantum-resistant signing method from the start.
Arc’s announcement comes as Google’s report on quantum threats to the Bitcoin and Ethereum blockchains raises new questions about the long-term reliability of digital ledgers. The developers, however, have been addressing the problem for months and proposing early solutions. At the same time, startups like Postquant Labs are exploring how quantum hardware could strengthen blockchain networks.
Arc’s choice to build quantum resistance from scratch could make it especially attractive to institutions. The blockchain launched its testnet in October, using Circle’s USDC stablecoin pegged to the dollar as the native currency for gas fees. USDC, with a market capitalization of around $77.5 billion, is only behind Tether in size and stands out as a regulated stablecoin favored by institutions.
Arc’s roadmap also includes ensuring that sensitive financial information remains private in the quantum age. Their near-term plan focuses on protecting private balances, sensitive payments, and recipient information with quantum-resistant cryptography, not just quantum-resistant wallet keys. This way, the sensitive financial activity of institutions using Arc will remain private.
The intermediate phase will focus on closing the back doors through which a quantum attack could occur. These backdoors are the cloud servers on which validators run, hardware security modules that store keys, and encrypted connections between nodes. This is similar to fortifying an entire building, not just the safe in your bedroom closet.
In the long term, Arc will focus on the validation layer. Validators are the computers, managed by trusted institutions, that confirm transactions and add new blocks to the distributed ledger.
Arc’s current design finishes a block in less than a second, according to the official blog. This leaves a future quantum attacker an extremely small window of time to obtain a user’s private key and forge a signature. The risk, therefore, is small, but Arc does not ignore it.
“Arc’s roadmap is expected to target strengthening the validator signature after rigorous performance testing and the necessary tooling support has been implemented. Validator upgrades should occur when they are ready to preserve both the resiliency and performance of the network,” he said.
