Random Number Generation in Operating Systems

Random number generation (RNG) plays a foundational role in security, cryptography, and system design. Operating systems today implement complex mechanisms for generating random numbers securely. This survey paper presents an overview of RNG techniques used in major operating systems, including Microsoft Windows, Linux, and macOS. We examine entropy sources, deterministic random bit generators (DRBGs), system APIs, and quality testing mechanisms. The survey highlights key differences between OS-level RNG designs and emphasizes best practices, challenges, and potential vulnerabilities. This work aims to serve as a reference for students, developers, and security professionals seeking a comparative understanding of secure randomness in computing environments.