Willison's Read on the Mythos Cryptanalysis: The Reusable Artifact Is the Prompt, Not the Attack
simonwillison.net·medium signal
Simon Willison's July 28 writeup argues the best part of Anthropic's cryptanalysis paper is the published prompts, quoting the researchers directly: 'the models tend to think it is impossible to solve so they don't try they need a good amount of prompting.' He notes the main human interventions across the 60-hour run were to encourage the model not to give up and to 'find something that's worth publishing.' For anyone running long-horizon agents, that is the transferable lesson — the failure mode on genuinely hard problems is premature abandonment, and the fix is a persistence instruction, not a bigger model.