Blockstream CEO Adam Back criticized Ethereum's early design decisions, describing its architecture as "obviously broken" and stating that Bitcoin's Unspent Transaction Output (UTXO) model reflects Satoshi Nakamoto's deeper understanding of distributed systems. This follows warnings from Ethereum researchers that AI could compromise crypto signatures in months. Ethereum co-founder Vitalik Buterin responded, advising against scrambling to move funds but emphasizing the need to take AI-accelerated mathematical risks to cryptography seriously.