Tens of thousands of encrypted messages from the last 500 years have survived in archives, libraries, collections, and attics. This includes encrypted dispatches from aristocrats and diplomats, encrypted military messages, encrypted telegrams, encrypted newspaper advertisements, encrypted postcards, encrypted diaries, and encrypted messages created by criminals. Previously unknown ciphertexts are discovered frequently.
DECODE, a database for historical ciphertexts, currently has about 8000 entries, and it keeps growing (https://de-crypt.org/decrypt-web).
While many of these old cryptograms are easily broken today, others are more difficult. And then, there are still numerous unsolved ciphertexts from the last 500 years. As a result of inter-disciplinary research, techniques for breaking historical ciphers have made considerable progress in recent years.
This presentation introduces the most important historical ciphers and modern techniques to break them - based on the 2023 book “Codebreaking: A Practical Guide” authored by the presenters. Many real-world examples are provided, with slides that use an entertaining style including Lego brick models, self-drawn cartoons, and animations.