How was the Enigma broken? Letters describing the details of capturing its prototype have survived

This article dives into the fascinating history of how the Enigma was cracked, focusing on the previously unknown correspondence of mathematician Marian Rejewski. It all started with a chance encounter at a customs office in Warsaw that sparked a major decryption operation. Rejewski's letters reveal his efforts to document Poland's crucial role in breaking German codes, which had been overlooked in British publications. It's a captivating glimpse into the past that highlights the importance of preserving such historical documents.