Fast randomness A diagram of the quantum random number generator on the photonic integrated chip. (Courtesy: Bing Bai and Yao Zheng) Smartphones could soon come equipped with a quantum-powered source ...

Random number sequences are essential to a host of encryption schemes. But true randomness in the strict sense is not possible in the classical world; it only occurs in quantum-mechanical processes.

To simulate chance occurrences, a computer can’t literally toss a coin or roll a die. Instead, it relies on special numerical recipes for generating strings of shuffled digits that pass for random ...