Generating truly random numbers is crucial for secure online communication, but doing so in a reliable way is still a challenge. A research team from the Indian Institute of Space Science and Technology (IIST), Thiruvananthapuram — Anirudh Shekar, Chirang R. Patel, Jerin A. Thachil, and Prof. Ashok Kumar — has developed a new method that uses light to create highly secure random numbers. The team used a process called four-wave mixing in rubidium-85 vapor to produce bright twin beams of light.