Many believe quantum attacks will be a black swan event for blockchain. However, for the Ethereum Foundation, quantum resistance has always been a crucial part of supporting major updates. Ethereum is well-prepared, even having an entire website dedicated to this aspect (see comments). The team has also drafted a roadmap based on the details of quantum resistance, with a series of updates scheduled until 2029 to ensure Layer 1 updates are completed by then. This report from Google also mentions zero-knowledge proofs, which serves as a good introduction to this technology. The EF team's stance is: they do not believe that cryptographically destructive quantum computers are imminent, but migrating a decentralized global protocol requires years of coordination, engineering, and formal verification, and must begin before the threat arrives. Besides Ethereum, other projects currently preparing for quantum resistance include Algorand, Solana, Hedera, the Bitcoin Network, IOTA, and ICP.