POWBlock is a universal bot/DDoS defense primitive for any server
Summary
POWBlock describes a PoW-based defense gate that sits behind reverse proxies to mitigate bot traffic and DDoS. It uses a JavaScript PoW challenge and a cookie-based token to allow legitimate users through, claiming high performance with minimal dependencies. The project emphasizes a small attack surface, hardware-oriented design, and deployment behind existing proxy stacks, with licensing implications noted.