True Random Numbers From Your Smartphone Camera?
The scientists experimented with an eight-megapixel camera from a Nokia N9, which like many smartphone cameras is sensitive enough to count the exact number of photons that strike each of its pixels. They illuminated the camera with a conventional LED. Due to quantum mechanics, the number of photons most light sources generate over any given time is random. Since the number of photons the camera’s pixels detects is random, it serves as the basis of the quantum random number generator.
The Nokia N9 can see true random numbers.
The Geneva-based scientists built a system consisting of the CMOS camera chip from a Nokia smartphone and a processor that used knowledge of the camera’s properties to turn the amount of charge at each pixel into a series of random numbers. (They looked into trying out an iPhone and some other models, but those did not have camera application programming interfaces that allowed access to the raw data from the pixels.)