Move over, legacy crypto. Circle’s Layer-1 blockchain Arc, built for stablecoin funding and institutional use, will debut 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 signature scheme that provides users with a practical design path to create quantum-resistant wallets,” Arc said in an update Thursday. The update did not mention the timeline for the mainnet launch.
This means that Arc bakes in quantum resistance from day one, unlike older chains that might wait to add this feature later as a patch. So when users create a wallet on the mainnet, they can choose a signature method that future quantum computers cannot break. This will ensure the long-term security and protection of crypto-assets in wallets.
Every blockchain wallet relies on a digital signature or super-secure key to prove you own 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. 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 so in at least two ways — a long attack and a short attack, as CoinDesk explained on Sunday.
In short, what looks unbreakable today may not be tomorrow, which is what Arc offers a quantum-resistant signature method right for bats.
Arc’s announcement comes as Google’s report on quantum threats to Bitcoin and Ethereum’s blockchains raises new questions about the long-term reliability of digital ledgers. However, developers have been tackling the issue for months and have proposed early fixes. At the same time, startups like Postquant Labs are investigating how quantum hardware can actually power blockchain networks.
Arc’s choice to build quantum resistance from scratch may make it particularly attractive to institutions. Blockchain started its testnet in October using Circle’s dollar-pegged stablecoin USDC as the initial currency for gas fees. USDC, with a market value of around 77.5 billion. USD, comes with band only 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 era. Its short-term plan focuses on protecting private balances, confidential payments and recipient information with quantum-resistant cryptography, not just quantum-resistant wallet keys. In this way, the confidential financial activity of institutions using Arc remains private.
The midway phase will focus on closing the back doors through which a quantum attack can occur. These backdoors are the cloud servers validators run on, the hardware security modules that store keys, and the encrypted connections between nodes. This is equivalent to fortifying an entire building, not just the safe in your bedroom closet.
In the longer term, Arc will focus on the validator layer. Validators are computers – run by trusted institutions – that confirm transactions and add new blocks to the distributed ledger.
Arc’s current design completes a block in under a second, according to the official blog. This leaves a future quantum attacker an extremely small window of time to derive a user’s private key and forge a signature. The risk is therefore small, but Arc does not ignore it.
“Arc’s roadmap is expected to target validator signature hardening after rigorous performance testing and the necessary tool support is in place. Validator upgrades should occur when ready to maintain both resiliency and network performance,” it said.
