Explore the evolution of digital currencies in this invited talk from Eurocrypt 2018, presented by Matthew Green. Delve into the history of electronic cash, from the early days of Digicash to the revolutionary blockchain technology. Examine the reasons behind the failure of centralized e-Cash systems and the emergence of Bitcoin in 2008. Analyze the impact, lessons, and limitations of Bitcoin, including privacy concerns and scalability issues. Investigate Layer 2 solutions like the Lightning Network and their implications for privacy. Learn about ledger-conditioned computation, potential vulnerabilities such as reset attacks and routine entropy failures, and gain insights into privacy-focused cryptocurrencies like Zerocoin. Access accompanying slides for a comprehensive understanding of this 30-year journey in digital currency innovation.