Go away, traditional cryptocurrencies. Circle’s Layer-1 blockchain Arc, built specifically for stablecoin financial and institutional use, will debut quantum-resistant features designed to cope with a future where traditional blockchains may collapse under quantum attacks.
“On mainnet, Arc will introduce a post-quantum signature scheme to provide users with a practical design path for creating quantum-resistant wallets,” Arc said in Thursday’s update, which did not mention a timeline for the mainnet launch.
This means Arc will be quantum resistant from day one, unlike traditional chains which may wait to add this feature later in the form of a patch. Therefore, when users create a wallet on mainnet, they can choose a signature method that will be unbreakable by future quantum computers. This will ensure the long-term security and protection of the crypto assets in the wallet.
Every blockchain wallet relies on digital signatures or super-secure keys to prove that you own the coins and authorize transactions. When you hit “send” on a cryptocurrency, your wallet signs the transaction using this code and the network verifies it before moving the coins. Today’s computers are not powerful enough to exploit this process, access your keys, and drain your coins.
However, as CoinDesk explained on Sunday, future quantum computers could do this in at least two ways — long attacks and short attacks.
In short, what seems indestructible today may not be tomorrow, and this is the quantum-resistant signature method provided by Arc.
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 the issue for months and have come up with early solutions. Meanwhile, startups like Postquant Labs are exploring how quantum hardware can actually enhance blockchain networks.
Arc chose to build quantum resistors from scratch, which may make it particularly attractive to institutions. The blockchain launched a testnet in October, using Circle’s USD-pegged stablecoin USDC as the native currency for gas fees. USDC’s market capitalization is approximately $77.5 billion, trailing only Tether It’s massive 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 immediate plans focus on using quantum-resistant cryptography (not just quantum-resistant wallet keys) to protect private balances, confidential payments, and recipient information. This way, the confidential financial activities of organizations using Arc remain private.
The mid-term phase will focus on closing backdoors through which quantum attacks could occur. These backdoors are the cloud servers running the validators, the hardware security modules that store the keys, and the encrypted connections between nodes. This is similar to hardening an entire building, not just the safe in a closet in a room.
In the long term, Arc will focus on the validator layer. Validators are computers run by trusted authorities that confirm transactions and add new blocks to the distributed ledger.
According to the official blog, Arc’s current design can complete a block in one second. This leaves a very short window for future quantum attackers to obtain the user’s private key and forge signatures. So the risk is minimal, but Arc isn’t ignoring it.
“Arc’s roadmap anticipates hardening for validator signatures after rigorous performance testing and necessary tooling support is in place. Validator upgrades should occur when ready to maintain resiliency and network performance,” it said.
