Circle unveils quantum-resistant roadmap for its layer-1 blockchain Arc

Stablecoin issuer Circle has released a post-quantum security roadmap for its layer-1 blockchain, Arc, aiming to implement solutions across all layers of the network’s tech stack.

Circle said on Thursday that it is planning a phased implementation, starting with quantum-proof wallets and signatures when Arc launches on mainnet. This feature will be opt-in, the company noted, while adding that solutions at the validator level and surrounding infrastructure will be implemented later on.

“Quantum resilience cannot live only in research papers, exploratory pilots, or distant roadmap slides. It has to show up in the infrastructure,” Circle said.

Circle’s roadmap comes as both Google and researchers at the California Institute of Technology recently warned that functional quantum computers could come sooner than expected, and require less computing power than previously thought. Google went as far as to say that quantum computers could potentially break Bitcoin’s cryptography in nine minutes.

“That is what makes inaction risky and why this conversation can't wait,” Circle said, while noting that “active addresses that have already signed transactions must migrate before Q-Day because their public keys have been exposed.”

Circle said a post-quantum signature scheme will be implemented on Arc when it launches on mainnet — expected sometime in 2026 — enabling quantum-resistant wallets. 

Arc is currently live on public testnet and will seek to enable enterprises to access a broad range of use cases with the USDC (USDC) stablecoin.

Sometime after mainnet launch, Circle will introduce a quantum solution that ensures balances, transactions and other financial data are private.

Over the long term, Circle said it will implement quantum solutions for Arc validators as well as its offchain infrastructure, including access controls, cloud environments and hardware security.

While most of the crypto industry agrees that quantum computing poses a legitimate threat to crypto, there remains debate over whether only crypto wallets with exposed public keys are vulnerable or whether all coins are at risk.

Many other crypto ecosystems are working on solutions

The Google research paper from March 31 noted that Algorand may be the most quantum-ready blockchain, while the Ethereum and Solana ecosystems are actively exploring solutions to be well-prepared before Q-Day.

Related: Is Bitcoin’s governance too slow to fend off quantum risks?

The Bitcoin ecosystem is more divided on what action developers should take.

One of the Bitcoin ecosystem’s strongest voices, Blockstream CEO Adam Back, says quantum risks are widely overstated and that no action is needed for decades.

On the other hand, security researcher Ethan Heilman and others have proposed a new output type for Bitcoin, called Pay-to-Merkle-Root, via Bitcoin Improvement Proposal 360 (BIP-360), which seeks to protect Bitcoin addresses from potential short-exposure quantum attacks.

However, that implementation may take seven years, Heilman told Cointelegraph in February.

Magazine: Nobody knows if quantum secure cryptography will even work