During the Renaissance, diplomats and monarchs relied heavily on encryption to protect state secrets. Substitution ciphers became more complex. Polyalphabetic ciphers — such as the Vigenère cipher — layered multiple substitutions to confuse codebreakers.
For centuries, such systems were considered unbreakable.
Until they weren’t.
Cryptanalysis — the art of breaking codes — evolved alongside cryptography. Pattern recognition, frequency analysis, and mathematical logic became powerful tools in the hands of skilled analysts.
It became a battle of minds: codemakers versus codebreakers.
World War II: The Codebreaking Revolution
Few moments in history highlight the importance of codebreaking more dramatically than World War II.
The German military relied heavily on the Enigma machine, an electromechanical encryption device that scrambled messages in seemingly infinite combinations.
The Nazis believed Enigma was unbreakable.
They were wrong.
At Bletchley Park in England, a team of mathematicians and cryptanalysts worked tirelessly to decode intercepted German transmissions.
