Quantum computers won’t break blockchain cryptography tomorrow. So why are we talking about them today? Week 1 was about understanding the technology before discussing the threat. Here are 7 key lessons: 1/ Classical computers use bits: 0 or 1. 2/ Quantum computers use qubits, which follow quantum mechanics. 3/ Superposition isn’t a collection of magical parallel answers. 4/ Entanglement creates correlations that have no classical equivalent. 5/ Quantum algorithms use interference to shape computational outcomes. 6/ Shor’s algorithm could threaten some cryptographic systems. 7/ Today’s quantum computers cannot break modern blockchain cryptography at practical scale. So why prepare now? Because upgrading cryptography takes time. Wallets, protocols, applications and infrastructure cannot all change overnight. Waiting until a threat becomes practical could be too late. Next week, we’ll get specific: What does quantum computing actually threaten in crypto: wallets, private keys, signatures or the blockchain itself? Which would you like to understand first: how quantum computers could threaten private keys, or how blockchains could defend against them?