A 200-year-old light trick just transformed quantum encryption

Scientists have unveiled a new approach to ultra-secure communication that could make quantum encryption simpler and more efficient than ever before. By harnessing a 19th-century optics phenomenon called the Talbot effect, researchers developed a system that sends information using multiple states of single photons instead of just two, dramatically boosting data capacity. Even more impressive, the setup works with standard components and requires only a single detector, reducing cost and complexity.