about this piece of a purple device is, if you look at it carefully, you'll be able to know that leo rosen was a gifted engineer and someone who had achieved success in an interesting way because the japanese had indeed built it with telephone switches. so rosen had been able to design a device, sight unseen, that was strikingly similar to the original. we talked a little about the debacle at pearl harbor, but let's move from tragedy to triumph, and talk about perhaps one of the best illustrations of why cryptology is so critical to nation states. we're going to talk about the battle of midway, and really despite the fact that it happened way back in 1942, there's no better example of showing how cryptology applied correctly in time of war can be what the military refers to as a force multiplier, something that can help you even the odds when you were at a great disadvantage. our story starts in the spring of 1942, and let's just say that the united states navy was not in a good position. we were down to about 50 ships, we had three aircraft carriers, about 47 other assorted craft. the jap