Question: What is the newest code?

Oliver Brown answered on 17 Mar 2015:

Hmm so the problem I have here is that the word ‘code’ means a *lot* of different things, so I’m not exactly sure what you mean. I’ll take a guess though (please correct me in a comment, or another question if I’m wrong!) that you might mean what is the newest encryption code — so a code which is used to make a message secret.

And to be honest, I don’t really know! The newest one that’s publicly available and commonly in use is RSA, which generates secret encryption keys by multiplying together two very large prime numbers. The prime numbers should be large enough that the resulting encryption key is between 2048 bits, and 4096 bits long in binary — that’s pretty big!