Quantum computing, often seen as a sword of Damocles hanging over blockchains, has fueled fantasies and speculations for more than a decade. In this universe of uncertainty, Vitalik Buterin, co-founder of Ethereum, presents a contrarian diagnosis: lucid, quantified, but above all, confident. For him, the arrival of machines capable of breaking current cryptographic foundations is not a fatality, it is a deadline. And Ethereum will be ready for it.