Joshua Holden shows how mathematical principles underpin the ways that different codes and ciphers operate, as he focuses on both code making and code breaking. He discusses the majority of ancient ...

Learn how to build a multivariate linear regression model step by step—no libraries, just pure C++ logic! Did military parade crowd leave en masse? What we know Can you leave chargers plugged in ...

This was the state of substitution cryptography before the advent of complex calculating machines. Soon, mechanical developments would make this sort of code look like child's play.

Technical Terms Substitution Box (S‐box): A fundamental component in block ciphers that performs non‐linear substitution to enhance the confusion property in encryption algorithms.

Some ciphers have simple keys, others, complex ones. The key for a cipher used by Augustus Caesar, some 2,000 years ago, was simple enough: The receiver just had to shift the alphabet one position.