Bletchley Park

I spent an interesting day at Bletchley Park, which is well worth a visit to learn not only about its pivotal role in the Second World War but also about cryptography and early computing. There is a memorial to the Poles as they were extremely helpful to the Allies.

In 1929, a German Enigma machine was being posted from Berlin to Warsaw and a couple of Germans went to the post office in Warsaw to collect it on a Friday afternoon. The Polish postmen didn't like the arrogant attitude of the Germans asking for this parcel and declared that they were too late, the parcel people had already left for the weekend and they'd have to come back on Monday. They then contacted the police. The parcel was opened and the curious machine revealed. The intelligence service was called in. Photographs were taken, engineers looked at its workings, its secrets were uncovered. The parcel was then resealed and the Germans collected it the following Monday, unaware of the interception.

The Poles were able to build copies of Enigma for themselves and then two brilliant men, M.Rejewski and H.Zygalski made machines which could decrypt the Enigma codes relatively quickly. These machines (Bombas) were up and running in 1938.

When it became clear that Poland was going to be invaded, the Poles contacted the British and French intelligence agencies and representatives from both countries went to Poland. They were told about the Bomba and each given a machine to take to safety. It is estimated that this action gave the Allies an intelligence advantage of six months.