Blockchain, Cryptocurrency. Bitcoin, Ethereum. Buzzwords? Trendy topics? Sure. As a developer, I'm not very interested in the hype or the crazy speculation. But I want to understand the underlying technology. How Bitcoin works. What makes Ethereum useful. The concepts and algorithms used by Bitcoin, Ethereum, and the thousands other coins that were created in the last years. I read the Bitcoin whitepaper. I found it very interesting. To share my new knowledge, I'd like to create a cryptocurrency in PHP... with you. One hour should be more than enough. Along the way, you will hopefully better understand what makes Bitcoin revolutionary.