Optimism has announced a 10-year plan to phase out ECDSA-based externally owned accounts (EOAs) on its OP Mainnet and the Superchain. This decision comes in anticipation of large-scale quantum computers, which could jeopardize the security of current cryptographic systems used in Ethereum. By January 2036, ECDSA-signed transactions will be deprecated, requiring all EOAs to transition to post-quantum smart contract accounts. This early announcement aims to give wallets, apps, and infrastructure providers ample time to prepare for this significant change. The migration will leverage account abstraction (AA) through EIP-7702, enabling EOAs to delegate their authority to smart contract accounts that can handle post-quantum signatures. Users don’t need to act immediately, as the focus is on establishing clear expectations and timelines. The actual transition will involve a coordinated hard fork across OP Mainnet and participating chains, allowing for parallel support of both ECDSA and post-quantum pathways during the migration period. Optimism intends to stay aligned with Ethereum on key upgrades, ensuring that the Superchain is prepared for a post-quantum future. The specific post-quantum signature scheme hasn’t yet been decided, but the team will evaluate options and adapt as needed. As the rollout progresses, they will provide detailed guides and migration paths to facilitate a smooth transition for developers and users alike.