Cryptography used to be the domain of information theorists and spies. There's a new player now: neural networks. Given the task of communicating securely, neural networks are inventing new encryption methods that, as best we can tell, are unlike anything humans have ever seen before.

Relevant links:

http://arstechnica.co.uk/information-technology/2016/10/google-ai-neural-network-cryptography/

https://arxiv.org/pdf/1610.06918v1.pdf