https://signal-and-syntax.com/categories/essays-and-perspectives/Recent content in Essays and Perspectives on Signal & SyntaxHugoen-usMon, 17 Nov 2025 06:00:00 -0700https://signal-and-syntax.com/posts/hash-collisions/Mon, 17 Nov 2025 06:00:00 -0700https://signal-and-syntax.com/posts/hash-collisions/In 2017, Google researchers generated two different PDF files with identical SHA-1 hashes, finally proving what cryptographers had warned about for years: hash functions don’t create truly unique fingerprints ( Stevens et al., 2017 ). This “SHAttered” attack required 9 quintillion SHA-1 computations, which is the equivalent to 6,500 years of single-CPU computation. The attack cost approximately $45,000 in cloud computing resources, making it accessible to well-funded adversaries but not casual attackers.https://signal-and-syntax.com/posts/tfp-chatgpt/Tue, 19 Aug 2025 05:00:00 -0700https://signal-and-syntax.com/posts/tfp-chatgpt/If ChatGPT can write code, summarize legal briefs, and help draft business strategies in seconds, why doesn’t that show up in our productivity statistics? Economists have long relied on a metric called Total Factor Productivity (TFP) to measure technological progress. But in an era of free digital tools and generative AI, TFP looks more like a rearview mirror than a windshield. It tells us a lot about the past, but almost nothing about where the economy is headed.