AI cracks Napoleon’s 200-year-old secret code in just six hours

In October 2026, artificial intelligence (AI) cracked a wartime message written in code by Napoleon Bonaparte more than 200 years ago. The message, dated 1809, contained the positions of French and allied troops in two dozen lines of symbols, numbers and letters. The message had remained unsolved in an online academic archive until AI engineer Carter Church deciphered it in just six hours using an advanced model from OpenAI.

Church, a 27-year-old AI engineer, described the achievement as a "turning point" in the field of historical cipher breaking, which is typically dominated by scholars and dedicated hobbyists. Traditional, low-tech methods of decoding ciphers are effective but time-consuming, causing many such puzzles to remain unattended. Church learned only "very little" about code-breaking techniques or the historical period and felt an "unbelievable sense of satisfaction and excitement" when he saw the result.

The breakthrough in AI-powered cipher cracking has been driven by the release of powerful general-purpose models, enabling non-specialists like Church to tackle these historical puzzles. While the technology has opened up new possibilities for historical research, researchers also express mixed feelings, as AI has solved difficult problems easily and may render the sense of accomplishment in solving these challenges obsolete.