Move over, old crypto. Circle’s Layer-1 blockchain Arc, built for stablecoin financing and institutional use, will debut with quantum-resistant features designed to survive a future where traditional blockchains could crumble under quantum attacks.
“On Mainnet, Arc will introduce a post-quantum signature scheme, giving users a practical design path to create quantum-resistant wallets,” Arc said in an update Thursday. The update did not mention a timeline for the mainnet launch.
It means that Arc offers quantum resistance from day one, unlike older chains, which might wait to add this feature as a patch later. So when users create a wallet on the mainnet, they can choose a signing method that future quantum computers can’t crack. This will ensure the security and protection of crypto assets in wallets in the long term.
Every blockchain wallet relies on a digital signature or a super-secure key to prove ownership of your tokens and authorize transactions. When you click “send” on your crypto, your wallet will sign the transaction with this code and the network will verify it before moving the coins. Today’s computers are not powerful enough to exploit this process, access your key and drain your coins.
However, a future quantum computer could do this 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 tomorrow, and that is what Arc immediately offers a quantum-resistant signing method.
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. However, developers have been working on addressing the problem and proposing early fixes for months. At the same time, startups like Postquant Labs are investigating how quantum hardware can actually strengthen blockchain networks.
Arc’s choice to build quantum resistance from the ground up could make it particularly attractive to institutions. The blockchain launched its testnet in October using Circle’s dollar-pegged stablecoin $USDC as the native currency for gas rates. $USDCwith a market capitalization of approximately $77.5 billion, remains limited in size and stands out as a regulated stablecoin preferred by institutions.
Arc’s roadmap also includes ensuring sensitive financial information remains private in the quantum age. The short-term plan focuses on protecting private balances, confidential payments and recipient information with quantum-resistant cryptography, not just quantum-resistant wallet keys. This way, the confidential financial activities of institutions using Arc remain private.
The medium-term phase will focus on closing the loopholes that could allow a quantum attack to occur. These backdoors are the cloud servers that run validators, the hardware security modules that store keys, and the encrypted connections between nodes. This is akin to fortifying an entire building, not just the safe in your room’s closet.
In the long term, Arc will focus on the validator layer. Validators are the computers – managed by trusted institutions – that confirm transactions and add new blocks to the distributed ledger.
According to the official blog, Arc’s current design completes a block in less than a second. This leaves an extremely small window for a future quantum attacker to derive a user’s private key and forge a signature. So the risk is small, but Arc does not ignore it.
“Arc’s roadmap is expected to focus on strengthening the validator signature after rigorous performance testing has been conducted and the necessary tooling support is in place. Validator upgrades should occur when ready to maintain both resiliency and network performance,” the report said.