Circle Adds Quantum-Resistant Protections to Arc Blockchain

Circle Internet Group is the issuer of the USDC stablecoin, while Arc is its Layer 1 blockchain built for stablecoin finance and institutional applications. Quantum computers could eventually break today’s public-key cryptography, threatening wallet signatures and verification systems. The industry has warned that “Q-Day” could arrive around 2030, making it particularly important to embed quantum-resistant protections at the protocol level in advance.

Circle unveiled Arc’s quantum-resistant security roadmap on April 2, 2026, with related reports published on April 6. When Arc’s mainnet launches in 2026, users are expected to have the option from day one to create quantum-resistant wallets using post-quantum signatures. Later phases will extend protection to private state, validator nodes, communications protocols and surrounding infrastructure, with the roadmap running through 2030.