Breaking Classical Ciphers

Cryptography · Axiom Academy

Discover the art and science of cryptanalysis - cracking secret codes and revealing hidden messages. Cryptanalysis is the study of breaking codes and ciphers. Click on the encrypted message below to start analyzing it. Types of Cryptanalytic Attacks Cryptanalysts use different types of attacks depending on what information they have. Click on each attack type to learn more. Pattern Recognition & Statistical Analysis One of the most powerful tools in cryptanalysis is frequency analysis. Observe how often each letter appears in this encrypted message. Breaking codes requires more than just math - it requires creative thinking. Match these encrypted patterns with likely plaintext words. Famous Code-Breaking Moments in History Throughout history, cryptanalysis has changed the course of wars, revealed secrets, and saved countless lives. Thomas Phelippes broke Mary's cipher, revealing her plot to assassinate Queen Elizabeth I. The decrypted letters were used as evidence in her trial, leading to her execution. This demonstrated how cryptanalysis could determine the fate of nations. British cryptanalysts in Room 40 decrypted a German telegram proposing a military alliance with Mexico against the United States. This revelation brought America into World War I and changed the war's outcome.

This is the written version of the interactive lesson above. See the full Cryptography course.