I've been reading up on Yubico's implementation of U2F. What I understand so far is that two things are calculated. So upon registration first you calculate a private key by $PrivateKey = ...
I wanted to learn about cryptography so they recommended me some of the books of Bruce Schneier. I'm now reading Cryptography Engineering and planning to follow with this one ...
Below is a Python code that calculates the periodicity of the middle-square method for a given 4 digit-numbers: ...