In 2016 a pair of researchers at Google Brain decided to see whether neural networks could develop cryptography. Their experiment was modeled on the use of an adversary, an increasingly common component of neural network designs wherein two competing elements attempt to outperform and outguess each other, driving further improvement. The researchers set up three networks called, in the tradition of cryptographic experiments, Alice, Bob, and Eve. Their task was to learn how to encrypt information. Alice and Bob both knew a number--a key, in cryptographic terms--that was unknown to Eve.